New simulation gives Jupiter double-sized core

New computer simulations, conducted at the scale of individual atoms, say Jupiter has a rocky core surrounded by ice that is more than twice as large as previously thought.

“We performed computer simulations of hydrogen-helium mixtures at high pressure and temperature conditions that occur inside Jupiter. Laboratory experiment cannot reach those extreme pressures yet,” says Professor Burkhard Militzer of the University of California, Berkeley, who calculated the properties of hydrogen and helium for temperature, density and pressure at the surface all the way to the planet's centre. Combined with known data for the planet’s mass, radius, surface temperature, gravity and equatorial bulge, co-author William Hubbard of the University of Arizona's Lunar and Planetary Laboratory used the theoretical data to build a new model for Jupiter's interior.

According to new simulations, Jupiter's core is twice as massive as originally believed. Image: NASA/R.J.Hall.

The new model suggests that Jupiter's core is an Earthlike rock 14 to 18 times the mass of Earth, equivalent to about one-twentieth of Jupiter's total mass, and with a metallic ball or iron and nickel at the centre. Previous models predicted a much smaller core of only seven Earth masses, or no core at all. The simulations also suggest that the core is made of layers of metals, rocks and ices of methane, ammonia and water, while above it is an atmosphere of mostly hydrogen and helium.

"Our simulations show there is a big rocky object in the centre
surrounded by an ice layer and hardly any ice elsewhere in the
planet,"says Militzer. "This is a very different result for the
interior structure of Jupiter than other recent models, which predict a relatively small or hardly any core and a mixture of ices throughout the atmosphere."

Militzer explains that hydrogen gradually changes from a molecular fluid in the outer layers to a metallic fluid in the deeper interior, which offers good electrical conductivity and gives rise to Jupiter's magnetic field. The homogeneous mantle is the key difference compared with older models that assume a different composition in the molecular and the metallic layers, giving rise to a smaller core.

"Our simulations show no evidence of any sharp phase transition, which led us to conclude that Jupiter's mantle is homogeneous in composition," he tells Astronomy Now. "The uncertainties in the previous models are why and where is there sharp transition and how does this change the chemical composition. No satisfactory explanation has been given, however, this is subject to further research. Our model is simpler because we assume the mantle is homogeneous since it does not make an assumption about a phase change."

Juno will reach Jupiter in 2016 and will make measurements of Jupiter's core. Image: NASA/Juno.

The results are bringing Jupiter's interior in line with that of Saturn, with a Neptune or Uranus at the centre. Neptune and Uranus are known as ice giants because they also appear to have a rocky core surrounded by icy hydrogen and helium, but without the giant gas envelopes of Jupiter and Saturn. The new Jupiter has ices that are concentrated in the outer layer of the core, while only a small amount, around one percent, is mixed in the hydrogen-helium gas envelope that contains 95 percent of the planet's mass.

The new model strongly supports the idea that Jupiter and other gas planets formed through the collision of small rocks that accreted to make a core, capturing a huge atmosphere of hydrogen and helium through its new-found gravitational attraction. "According to the core accretion model, as the original planetary nebula cooled, planetesimals collided and stuck together in a runaway effect that formed planet cores," says Militzer. "If true, this implies that the planets have large cores, which is what the simulation predicts. It is more difficult to make a planet with a small core."

In order to match the observed gravity of Jupiter, Militzer's
simulation also predicts that different parts of Jupiter's interior rotate at different rates. Jupiter can be thought of as a series of concentric cylinders rotating around the planet's spin axis, with the outer cylinders - the equatorial regions - rotating faster than the inner cylinders, in a similar fashion to how the Sun rotates. Future data from NASA's Juno mission, to be launched in 2011 and reaching Jupiter by 2016, will measure the planet's magnetic field and gravity, and provide a check on Militzer and Hubbard’s predictions.

The team also plan to use the new model to simulate other planets' interiors, and to investigate the implications for the formation of planets outside our Solar System

from:astronomynow.com

Buried ice found at low latitudes on Mars

NASA's Mars Reconnaissance Orbiter has revealed vast Martian glaciers of water ice buried under protective blankets of rocky debris at much lower latitudes than any ice previously identified on the Red Planet.

Using the spacecraft’s ground-penetrating radar instrument, which can see up to one kilometre below the surface of the planet, scientists have discovered that buried glaciers extend laterally for dozens of kilometres from the edges of mountains or cliffs in the Hellas Basin region of Mars' southern hemisphere.

Artist impression of an exposed glacier on Mars. Image: NASA/JPL.

"Altogether, these glaciers almost certainly represent the largest
reservoir of water ice on Mars that is not in the polar caps," says John Holt of the University of Texas at Austin, and lead author of the report that appears in the 21 November issue of the journal Science. "Just one of the features we examined is three times larger than the city of Los Angeles and up to half a mile thick. And there are many more. In addition to their scientific value, they could be a source of water to support future exploration of Mars."

Scientists have long been puzzled by the appearance of features known as ‘aprons’, gently sloping areas containing rocky deposits at the bases of taller geographical features, since NASA's Viking orbiters first observed them on the Martian surface in the 1970s. One theory has been that the aprons are flows of rocky debris lubricated by a small amount ice. The Mars Reconnaissance Orbiter has finally provided scientists with an answer to this long-lived mystery.

"These results are the smoking gun pointing to the presence of large amounts of water ice at these latitudes," says Ali Safaeinili, a shallow radar instruments team member with NASA's Jet Propulsion Laboratory. Radar waves are sensitive to changes in the electrical reflection characteristics of rock, sand or water. Water returns a particularly strong signal, and the latest measurements report that the radio waves pass straight through the aprons and reflect off a deeper surface below, without significant loss in strength. The readings imply that the aprons are composed of thick ice under a relatively thin covering of rock, and rule out the presence of a significant amount of rocky debris within the ice.

A large portion of a debris apron along the bottom of a hill on Mars. Scientists have long suspected that ice may be involved with ‘softening’ the appearance of these features, and radar has now revealed them to be hiding vast reservoirs of ice beneath a rocky surface. Image: NASA/JPL/University of Arizona.

It is now a priority to observe other examples of these aprons seen in different areas of Mars to determine whether they are also hiding ice. "There's an even larger volume of water ice in the northern deposits," says JPL geologist Jeffrey Plaut. "The fact these features are in the same latitude bands, about 35 to 60 degrees in both hemispheres, points to a climate-driven mechanism for explaining how they got there."

It is likely that the ice sheets were laid down during a previous ice age on Mars, and scientists suspect that the rocky debris blanket topping the glaciers has protected the ice from vapourising, which would happen if it were exposed to the atmosphere at these latitudes. The discovery is similar to massive ice glaciers that have been detected under rocky coverings in Antarctica.

"The tilt of Mars' spin axis sometimes gets much greater than it is now,” says James W Head of Brown University. “Climate modelling tells us ice sheets could cover mid-latitude regions of Mars during those high-tilt periods. The buried glaciers make sense as preserved fragments from an ice age millions of years ago.”

On Earth, buried glacial ice in Antarctica preserves the record of traces of ancient organisms and past climate history. Who knows what secrets the buried Martian glaciers are keeping.

from:astronomynow.com

A localised cosmic ray influx

Research conducted at the Milagro observatory has uncovered two nearby regions in space that exhibit unusually high readings of cosmic rays.

This is the second finding of a source of near-Earth galactic cosmic rays announced in the past week; scientists working on the ATIC experiment reported a surplus of cosmic ray electrons near to the Earth in the 20 November issue of the journal Nature. You can read our report here.

"These two results may be due to the same, or different, astrophysical phenomenon,” says Jordan Goodman of the University of Maryland and principal investigator for Milagro. "However, they both suggest the presence of high-energy particle acceleration in the vicinity of the Earth. Our new findings point to general locations for the localised excesses of cosmic-ray protons observed with the Milagro observatory."

Showers of high energy particles occur when high energy particles strike the top of the atmosphere. Image: Simon Swardy/U. Chicago/ NASA.

Cosmic rays are charged particles, including protons and
electrons, that are accelerated to high energies from sources both outside and inside our Galaxy. It is unknown exactly what creates these cosmic rays, but likely culprits may include supernovae, quasars or even more exotic processes involving dark matter. Until recently, it was widely believed that cosmic ray particles bombarded the Earth uniformly from all directions. These new findings are the strongest indications yet that the distribution of cosmic rays is much more variable.

"Whatever the source of the protons we observed with Milagro, their path to Earth is deflected by the magnetic field of the Milky Way so that we cannot directly tell exactly where they originate," says Goodman. "And whether the regions of excess seen by Milagro actually point to a source of cosmic rays, or are the result of some other unknown nearby effect is an important question raised by our observations."

Based on seven years worth of observations of the entire sky above the northern hemisphere, and over 200 billion cosmic ray collisions with the Earth's atmosphere, the researchers could see statistical peaks in the number of cosmic ray events originating from relatively small regions of the sky. An excess of cosmic ray protons were found in an area above and to the right of Orion, near the constellation Taurus. The other hot spot was identified as comma-shaped region in the sky near the constellation Gemini.

The Milagro Observatory is located under several metres of water to enhance cosmic ray particle detections. Image: Milagro Observatory.

The Milagro observatory is located in a 60 x 80 x 8 metre covered pond in the Jemez Mountains near Los Alamos, New Mexico, and detects cosmic rays by observing the energetic secondary particles that make it to the surface. The Earth’s atmosphere protects us from direct strikes of high energy cosmic ray particles and when a high-energy cosmic ray enters the atmosphere it loses its energy via interactions with the nuclei that make up the air. These interactions create a large cascade of secondary particles in an ‘air shower’. The particles in the air shower interact much more quickly with water than air, and generate more detectable particles in water, which is why cosmic ray detectors are usually encased in water.

Future observations of cosmic rays may come in the form of a new observatory that Goodman and colleagues have proposed to the National Science Foundation. This second-generation experiment named the High Altitude Water Cherenkov experiment (HAWC) would be built at a high altitude site in Mexico.

from:astronomynow.com

More evidence for water reservoir at Enceladus

Scientists have found more evidence to suggest that the geyser like plumes spewing out from Saturn’s icy moon Enceladus may be sourced from a warm liquid ocean buried deep within the moon.

Using data collected by the Cassini spacecraft's Ultraviolet Imaging Spectrograph, scientists from the Jet Propulsion Lab, the University of Colorado and the University of Central Florida see evidence for vents channelling water vapour from the liquid reservoir to the surface at supersonic speeds, supporting a mathematical model proposed last year.

Are Enceladus' jets sourced by a warm liquid water ocean buried deep within the icy moon? The debate continues. Image: NASA/JPL/Space Science Institute.

"There are only three places in the Solar System we know or suspect to have liquid water near the surface," says Professor Joshua Colwell of the University of Central Florida. "Earth, Jupiter's moon Europa and now Saturn's Enceladus. Water is a basic ingredient for life, and there are certainly implications there. If we find that the tidal heating that we believe causes these geysers is a common planetary systems phenomenon, then it gets really interesting."

On Earth, liquid water exists four kilometres below ice at Lake Vostok and in some 140 other shallower lakes in Antarctica, so the possibility of similar reservoirs on other planetary bodies is not out of the question. Indeed, many groups of scientists working on Cassini data suspect that a liquid ocean is a strong possibility for Europa.

One recent theory proposes that the jets could be violent bursts of volatile ices that suddenly become exposed to space when Saturn’s tidal forces open and close the tiger stripes at Enceladus’ south pole. The new results, however, cast doubt on this idea. Instead the team found more water vapour coming from the vents at times when the theory predicted there should have been less. That is, at times when Enceladus is further away from Saturn, the vents would compress, reducing or shutting off the jets completely.

"Our observations do not agree with the predicted timing of the
faults opening and closing due to tidal tension and compression," says Candice Hansen, the lead author on the project. "We don't rule it out entirely, but we also definitely do not substantiate this hypothesis."

By observing the flickering light of a star as the geysers impaired a direct view of it on two occasions in 2005 and 2007, the team made measurements of the water vapour content and density of the jets. Theory predicted that more water vapour would be recorded in 2005 when the vents were open than in 2007 when they were closed. But Hansen and colleagues found that the 2007 plume was twice as dense as in 2005, the direct opposite of the original prediction. Their results are presented in the 27 November issue of the journal Nature.

Hansen’s work supports an earlier idea that the vents are like nozzles, focussing the water vapour from depth to the surface at supersonic speeds. They propose that ice grains would condense from the vapour and stream through the cracks in the ice crust before heading into space. The team conclude that only high temperatures close to the melting point of water ice could account for the high speed of the water vapour jets.

Whether there is liquid water present still remains uncertain, but if conclusive evidence arises there would be strong implications for Enceladus as a potential environment to support life. Enceladus will remain a high priority target throughout Cassini’s extended Equinox Mission, which will continue until September 2010.

from:astronomynow.com

Milky Way’s mammoth stars resolved by Hubble

Two of our Galaxy's most massive stars have been scrutinised by the Hubble Space Telescope to reveal a third component of the system.

The pair of mammoth stars, WR 25 and Tr16-244, are located within the open cluster Trumpler 16, which itself is embedded within the Carina Nebula around 7,500 light years from Earth. Many stars in the Carina Nebula, including the highest luminosity star known, Eta Carinae, are ultra bright, hot stars, emitting most of their radiation in the ultraviolet and appearing blue in colour. They burn so ferociously that they power through their hydrogen fuel source faster than any other type of star.

WR 25 is situated near the centre of the image in the bottom third. Tr16-244 is located to the upper left of WR 25. The star to the left of WR 25 is a low mass star located much closer to the Earth. The massive stars are thought to be responsible for the radiation that is creating a giant gas bubble, and controlling the globule's interesting shape, which includes a finger-like shape pointing towards WR 25 and Tr16-244. Image: NASA, ESA, and J. Maíz Apellániz (Instituto de Astrofísica de Andalucía, Spain).

WR 25 and Tr16-244 interest astronomers because they are associated with star-forming nebulae, and influence the structure and evolution of galaxies. Such massive stars are usually formed in compact clusters, and combined with their extreme brightness, makes the study of any individual star very difficult. New Hubble observations have come to the rescue. Obtained by a team of scientists from US, Chilean, Spanish, and Argentine institutions and led by Jesus Maiz Apellaniz from the Instituto de Astrofisica de Andalucia in Spain, astronomers have been given an even finer look at the system, revealing that the pair is actually a triple star system. The third star takes tens or even hundreds of thousands of years to orbit the other two stars.

The true nature of WR 25 was revealed two years ago when astronomers discovered that it was actually composed of two stars. WR 25 is the more massive Wolf-Rayet star and may weigh more than 50 times the mass of our Sun. It is losing mass rapidly through powerful stellar winds that have ejected the majority of its outermost hydrogen-rich shells, while its more commonplace binary companion is roughly half as massive, orbiting around it once every 208 days.

Two of the stars are so close to each other that they look like a single object, but Hubble's Advanced Camera for Surveys reveals them as two. Image: NASA, ESA, and J. Maíz Apellániz (Instituto de Astrofísica de Andalucía, Spain).

Astronomers believe that WR 25 and Tr16-244 are the likely sources of radiation that is causing a giant gas globule within the Carina Nebula to slowly evaporate away into space, while possibly inducing the formation of new stars within it.

The research team are using Hubble as well as ground-based observatories in Spain, Chile, and Argentina to build a comprehensive catalogue of observations of all the massive stars in the Galaxy that are detectable at visible wavelengths.

from:Astronomynow.com

Nature of ‘Hanny's Voorwerp’ revealed

Radio observations of a curious feature brought to the attention of astronomers by Dutch Galaxy Zoo volunteer Hanny van Arkel have finally revealed the nature of the object that came to be known as Hanny’s Voorwerp.

Like many ordinary Galaxy Zoo volunteers, Hanny was surfing through hundreds of galaxy images when she stumbled across a huge green irregular cloud of gas located about 60,000 light years from a nearby galaxy, IC 2497. Nicknamed Hanny’s Voorwerp (Dutch for object), its nature and origin have had astronomers scratching their heads for over a year.

The green gas cloud bears temperatures of over 15,000 degrees Celsius, but curiously, it is devoid of stars. Using the Westerbork Synthesis Radio Telescope (WSRT) and an e-VLBI array, an international team of astronomers led by Professor Mike Garrett of the Netherlands Institute for Radio Astronomy (ASTRON), and including Hanny van Arkel herself, have observed IC 2497 and the Voorwerp, to dig deeper into the mystery.

WSRT observations reveal a radio jet (white contours) emanating from the centre of the nearby galaxy IC 2497, headed straight in the direction of Hanny's Voorwerp (green). The observations also reveal a huge reservoir of hydrogen gas (coloured orange) that probably arose from a previous encounter between IC2497 and another galaxy. The presence of strong neutral hydrogen absorption (top right plot) argues that the central regions of IC2497 are highly obscured. Image: ASTRON/Dan Herbert/Isaac Newton Telescope.

The observations reveal a jet of highly energetic particles that are being generated by none other than a massive black hole lurking at the centre of the neighbouring galaxy. "It looks as though the jet emanating from the black hole clears a path through the dense interstellar medium of IC 2497 towards Hanny's Voorwerp", says Garrett. "This cleared channel permits the beam of intense optical and ultraviolet emission associated with the black hole to illuminate a small part of a large gas cloud that partially surrounds the galaxy. The optical and ultraviolet emission heats and ionises the gas cloud, thus creating the phenomena known as Hanny's Voorwerp.”

Another question that astronomers had was ‘where does all the hydrogen gas come from?’ The total mass of gas is about 5,000 million times the mass of the Sun and extends across hundreds of thousands of light years. Team member Dr Tom Oosterloo thinks that it has all the hallmarks of an interacting system. “The gas probably arises from a tidal interaction between IC 2497 and another galaxy, several hundred million years ago,” he says. "The stream of gas ends three hundred thousand light years westwards of IC2497 - all the evidence points towards a group of galaxies at the tip of the stream being responsible for this freak cosmic accident".

Hanny van Arkel shares the excitement of the professional team of astronomers, and visited ASTRON to find out more about the object she stumbled upon. "I'm happy we are making progress,” she says. “Apparently the more we learn about the Voorwerp, the more intriguing it becomes".

The team still think that the Voorwerp has a few more secrets to reveal, and plan much deeper observations with the WSRT and other higher resolution radio telescopes soon.

from:Astronomynow.com

Galaxy evolution: nature or nurture?

UK astronomers working on data from two separate projects - Galaxy Zoo and the Space Telescope A901/902 Galaxy Evolution Survey (STAGES) - have both uncovered a type of galaxy that represents a missing link in galaxy evolution.

Astronomers broadly divide galaxies into two categories according to their shape: either disc-like systems like our own Milky Way which exhibits spiral arms, or round, rugby-ball shaped collections of stars known as ellipticals. In most cases, a galaxy's shape matches its colour: spiral galaxies appear blue because they are still vigorously forming hot young stars, while elliptical galaxies are mostly old, dead and red, and tend to cluster together in crowded regions of space.

But new results, based on two independent studies, reveal a population of unusual spiral galaxies that appear red. "In order to have spiral arms, they must have been normal, blue, spiral galaxies up until fairly recently,” says Dr Steven Bamford of the University of Nottingham who led the Galaxy Zoo study. “But for some reason their star formation has been stopped, and they have turned red. Whatever caused them to stop forming stars can't have been particularly violent, or it would have destroyed the delicate spiral pattern."

These images of three galaxies from the Galaxy Zoo (top) and STAGES surveys (bottom) show examples of how the newly discovered population of red spiral galaxies on the outskirts of crowded regions in the Universe may be a missing link in our understanding of galaxy evolution. The left hand galaxies show young blue spiral galaxies and the right are examples of elliptical galaxies containing old, red stars. The central images show the new class of red spiral galaxy, thought to be changing from blue spirals into red as star formation has been shut off by interactions with the environment. Image: Hubble Space Telescope/COMBO-17 survey/Marco Barden, Christian Wolf, Meghan Gray (STAGES) & Sloan Digital Sky Survey (Galaxy Zoo).

While Galaxy Zoo looked at the gross properties of millions of
galaxies across a large area of sky, the STAGES project examined in detail the types of neighbourhood where transformations between the two types of galaxies are expected to occur, such as the A901/902 supercluster of spiral galaxies. Using the Hubble and Spitzer Space Telescopes, the STAGES team uncovered a surprisingly large population of red spiral galaxies.

"For the STAGES galaxies, the Spitzer Space Telescope provided us with additional images at infrared wavelengths,” says STAGES scientist Dr Christian Wolf of the University of Oxford. “With them, we were able to go further and peer through the dust to find the missing piece of the puzzle". Wolf discovered that the red spirals were hiding low levels of hidden star formation, despite their otherwise lifeless appearance in visible light.

Astronomers have used the complementary observations to come up with a new theory of how nature and nurture have both played a significant role in these galaxies’ evolution. They suggest that star formation in blue spiral galaxies is gradually shut off and hidden behind dust, before slowly smoothing out to form lens-shaped red galaxies with no trace of spiral arms. To directly transform the galaxy into an elliptical would require collisions of galaxies.

The local environment of the galaxy also turns out to be important in determining when and how quickly its star formation is shut down. The red spirals are found primarily on the outskirts of crowded regions of space where galaxies cluster together. As a blue galaxy is drawn into the cluster by gravity, an interaction with its environment causes a slow-down in star formation. The astronomers see that the further in a galaxy is, the more it is affected by its environment.

The Abell 901/902 supercluster as seen by COMBO-17 in the STAGES survey. This complex system provides an ideal laboratory for studying the links between environment and galaxy evolution. Image: STAGES/COMBO-17/HST.

But if environment decides where the process occurs, the two teams also found that the mass of the galaxy decides how quickly it takes place. "Just as a heavyweight fighter can withstand a blow that would bring a normal person to his knees; a big galaxy is more resistant to being messed around by its local environment,” explains Galaxy Zoo team member Professor Bob Nichol of Portsmouth University. “Therefore, the red spirals that we see tend to be the larger galaxies - presumably because the smaller ones are transformed more quickly."

The next step for both teams is to find out exactly what shuts off the star formation, by looking inside the galaxies themselves. One suspect behind the slow demise of galaxies is a process known as strangulation, in which a galaxy's fuel supply is stripped away as it encounters a crowd of galaxies. Starved of the raw material needed to form new stars, it will slowly change colour from blue to red as its existing stars age.

"These results are possible thanks to a major scientific
contribution from our many volunteer armchair astronomers,” says Galaxy Zoo team leader Chris Lintott. “No group of professionals could have classified this many galaxies alone.”

The original Galaxy Zoo launched in the summer of 2007 and saw over 150,000 visitors classify one million galaxies, resulting in enough data to fill some six scientific papers. Galaxy Zoo 2 is currently being prepared to answer more detailed questions about the morphologies of around 250,000 galaxies from the original survey in order to compile the most comprehensive data set of galaxy shapes yet.

from:http://astronomynow.com/081126galaxyevolutionnatureornurture.html

Chandrayaan-1 Moon probe a big hit

India’s first mission to the Moon, Chandrayaan-1, has begun making science observations and successfully deployed its Moon Impact Probe at the lunar south pole.

The 29 kilogram Moon Impact Probe (MIP) was dropped close to Shackleton crater, where ice is thought to exist in areas that are permanently in shadow. The probe carried three instruments: a video imaging system, a radar altimeter and a mass spectrometer, which took images, determined altitude and studied the thin lunar atmosphere during the 25 minute descent, respectively. The data was transmitted back to the orbiter and later downloaded to Earth.

Two raw images of the lunar surface taken by the camera on the Moon Impact Probe after separating from Chandrayaan-1. Image: ISRO.

The probe struck the lunar surface at a velocity of 1.5 kilometres per second. “The precise point where the MIP went down is still being analysed,” says Detlef Koschny, Chandrayaan-1 project scientist for ESA. “It was not controlled and the intention was simply to get it down in the area of the South Pole, not to go inside of Shackleton.”

The main goal of the MIP was a technology demonstration to show that scientific analysis could be performed during the probe’s descent, and the science team are currently putting together the data for public consumption. The impact speed in this case was too low to throw up any dust or ice but that is one of the goals of NASA’s upcoming LCROSS mission that should excavate material from one of the Moon’s dark south pole craters, and will finally confirm the presence or absence of water ice there. The identification of water is very important to the future of human activities on the Moon.

The rest of Chandrayaan-1’s instruments are now beginning science operations, once completing a commissioning phase. That is, all the standard modes of each instrument are tested by carrying out routine ‘housekeeping’ activities to verify that everything is working properly. The European Space Agency is involved with three instruments - C1XS (Chandrayaan-1 X-ray Spectrometer), SARA (Sub-keV Atom Reflecting Analyser) and SIR-2 (a near-infrared spectrometer), of which SIR-2 has already begun science observations, C1XS is performing routine tests and SARA will be commissioned in the coming weeks. “Full science operations will begin mid-December, of course pending successful instrument commissioning,” says Koschny.

C1XS, SARA and SIR-2 will all map the Moon’s composition in different ways. C1XS, built by UK scientists and engineers, will quantify the Moon’s mineral resources and is expected to unearth clues regarding the origin of the Earth-Moon system. SARA will investigate the space environment around the Moon, and the interactions of the solar wind with the Moon's surface. SIR-2 will survey the Moon's mineral composition and the effect of space weathering, since in the absence of an atmosphere the Moon’s barren surface is exposed directly to the harsh environment of space. Accurate maps of the Moon’s surface composition will help planetary scientist unravel the Moon’s geological history, which will help us better understand the origin of the Earth-Moon system. The results are also expected to teach us more about what happened on the Moon since it formed and how and when it cooled.

from:http://astronomynow.com/081125Chandrayaan1Moonprobeabighit.html

First map of Mars’ aurorae

Scientists using ESA's Mars Express have produced the first crude map of aurorae on Mars.

The aurorae on Mars were first discovered in 2004 using the SPICAM ultraviolet and infrared atmospheric spectrometer onboard Mars Express, which revealed displays of ultraviolet light associated with the residual magnetic fields generated by Mars' crustal rocks. Now, using coordinated observations from SPICAM, the MARSIS sub-surface sounding radar altimeter's radar, and the energetic neutral atoms analyser ASPERA, Francois Leblanc from the Service d'Aeronomie and colleagues have observed nine new auroral emission events, which have allowed them to make the first crude map of auroral activity on Mars.

Artist impression of how the 'green' aurorae may look to an observer orbiting on the night-side of Mars. Image: M. Holmström (IRF).

The observations show that the aurorae seem to be located near regions where the Martian magnetic field is the strongest, confirming earlier MARSIS detections of higher-than-expected electrons in similar regions. This tentatively suggests that the magnetic fields help to create the aurorae, but there is still a lot of work to do in determining how they arise, since Mars lacks the same large scale internal mechanism that drives the magnetic fields on other planets. Instead, it just generates small pockets of magnetism where areas of rocks in the crust of Mars are themselves already magnetic, resulting in many magnetic pole-type regions all over Mars.

On Earth, aurorae are usually confined to the polar regions and shine brightly in visible light as well as at ultraviolet wavelengths. The existence of similar aurorae is also well known on the giant planets of the Solar System and occur wherever a planet's magnetic field channels electrically charged particles blown out from the Sun in the solar wind into the planet’s atmosphere. But how the electrons are accelerated to sufficiently high energies to spark aurorae on Mars remains a mystery. "It may be that magnetic fields on Mars connect with the solar wind, providing a road for the electrons to travel along," says Leblanc.

Terrestrial aurorae are displayed typically in reds and greens, as a result of the interaction of molecular and atomic oxygen and molecular nitrogen in the atmosphere with the solar wind particles. These molecules are not abundant enough in the Martian atmosphere and so it is uncertain if similar light shows would be observed from the red planet’s surface. Furthermore, SPICAM is designed to work at ultraviolet wavelengths and cannot see whether visible light is being emitted as well. But the new results will provide plenty of work for the scientists in the months and years to come, and will offer new insight to the composition and structure of the Martian atmosphere and how the planet interacts with electrically charged particles originating from the Sun.

"There's now a large domain of physics that we have to explore in order to understand the aurorae on Mars,” says Leblanc. “Thanks to Mars Express we have a lot of very good measurements to work with."

from:http://astronomynow.com/081124FirstmapofMarsaurorae.html

Beta Pictoris planet finally imaged?

Inside the debris disc of Beta Pictoris lies a newly discovered object. If confirmed as a gas giant, it will be the first image of a planet that is as close to its host star as Saturn is to the Sun.

The hot star Beta Pictoris is one of the best known examples of stars surrounded by a debris disc – the dusty remains of past collisions among planetary building blocks and asteroids. Previous observations of the system revealed a peculiar shape to the disc, a secondary inclined disc, and comets tumbling towards the central star. With a projected distance from the star of only eight times the Earth-Sun distance, the new object discovered by a team of French astronomers using ESO's Very Large Telescope is most likely a giant planet that astronomers suspected might be lurking there all along.

"These are indirect, but tell-tale signs that strongly suggest the presence of a massive planet lying between five and ten times the mean Earth-Sun distance from its host star," says team leader Anne-Marie Lagrange. "However, probing the very inner region of the disc, so close to the glowing star, is a most challenging task."

This composite image represents the close environment of Beta Pictoris as seen in near infrared light. The newly detected source is more than 1000 times fainter than Beta Pictoris, aligned with the disc, at a projected distance of eight times the Earth-Sun distance. Image: ESO/A.-M. Lagrange et al.

The team imaged the Beta Pictoris system around five years ago using the NAOS-CONICA instrument (NACO) mounted on one of the 8.2 metre units of the Very Large Telescope (VLT). Recently, a member of the team re-analysed the data in infrared to seek the trace of a companion to the star. "For this, the real challenge is to identify and subtract as accurately as possible the bright stellar halo," explains Lagrange. "We were able to achieve this after a precise and drastic selection of the best images recorded during our observations."

A feeble, point-like glow well inside the star's halo was discerned, with independent analysis throwing up the same result: the companion is real. "Our observations point to the presence of a giant planet, about eight times as massive as Jupiter and with a projected distance from its star of about eight times the Earth-Sun distance, which is about the distance of Saturn in our Solar System," says Lagrange.

However, the team cannot yet rule out the possibility that the candidate companion could be a foreground or background object, and so the team will have to make some more observations to confirm the nature of the discovery, although the fact that the object lies in the plane of the star’s disc strongly implies that it is bound to the star and its proto-planetary disc. "Moreover, the candidate companion has exactly the mass and distance from its host star needed to explain all the disc's properties. This is clearly another nail in the coffin of the false alarm hypothesis," adds Lagrange.

Once confirmed, this candidate companion will be the closest planet from its star ever imaged directly, although planets have been inferred orbiting closer to their host stars in other studies using different methods. By studying different planetary systems, scientists can learn about the different formation processes of planets at varying distances from their host stars.

"Direct imaging of extrasolar planets is necessary to test the various models of formation and evolution of planetary systems. But such observations are only beginning,” says team member Daniel Rouan. “Limited today to giant planets around young stars, they will in the future extend to the detection of cooler and older planets, with the forthcoming instruments on the VLT and on the next generation of optical telescopes."

Beta Pictoris is 12 million years old and located about 70 light years away from Earth towards the constellation Pictor.

from:http://astronomynow.com/081124BetaPictorisplanetfinallyimaged.html

Hubble resolves mystery of lone starburst galaxy

Astronomers have solved the mystery as to why a small, nearby, isolated galaxy is pumping out new stars faster than any galaxy in our local neighborhood. It turns out it is actually further away than astronomers first thought.

The discovery happened by accident while Alessandra Aloisi and colleagues from the Space Telescope Science Institute in Baltimore and the European Space Agency were using Hubble to search galaxy NGC 1569 for red giant stars. Red giants can be used to estimate a galaxy's age since they are reliable ‘standard candles’ for measuring distance because they all shine at the same brightness.

"When we found no obvious trace of them, we suspected that the galaxy was farther away than originally believed," says Aaron Grocholski. "We could only see the brightest red giant stars, but we were able to use these stars to re-calibrate the galaxy's distance."

NGC 1569's core is made up of three giant star clusters, each containing more than a million stars. New analysis place the galaxy at a distance of 11 million light years from Earth. Image: NASA/ESA/STScI/AURA/Hubble Heritage Team/A.Aloisi.

Previous estimates of the galaxy's distance were made with ground-based telescopes and were unreliable because they looked at the galaxy's crowded core and were unable to resolve individual red giant stars. Hubble was able to resolve both the galaxy's cluttered core and its sparsely populated outer fringes, identifying individual red giants, and therefore allowing a precise distance to the galaxy to be determined.

"This was a serendipitous discovery," says Aloisi. "Hubble didn't go deep enough to see the faintest red giant stars we were hunting for because the galaxy is farther away than we thought. However, by capturing the entire population of the brightest red giant stars, we were able to calculate a precise distance to NGC 1569 and resolve the puzzle about the galaxy's extreme starburst activity."

The new observations reveal that it is located around one and a half times farther away than astronomers previously thought, at a distance of nearly 11 million light years. The extra distance places the galaxy in the middle of a group of about 10 galaxies centred on the spiral galaxy IC 342. Gravitational interactions among the group's galaxies may be compressing gas in NGC 1569 and igniting the frenetic bout of star formation, which is over 100 times higher than star formation in the Milky Way.

"Now the starburst activity seen in NGC 1569 makes sense, because the galaxy is probably interacting with other galaxies in the group," says Aloisi. "Those interactions are probably fueling the star birth."

This type of starburst galaxy is thought to drive the evolution of galaxies in the distant and young Universe. "Starburst galaxies can only be studied in detail in the nearby Universe, where they are much rarer,” says Roeland van der Marel. “Hubble observations of our galactic neighborhood, including this study, are helping astronomers put together a complete picture of the galaxies in our local Universe. Put the puzzle pieces in the right place, as for NGC 1569, and the picture makes much more sense."

The results are published in the 20th October issue of the journal Astrophysical Journal Letters.

from:http://astronomynow.com/081121Hubbleresolvesmysteryoflonestarburstgalaxy.html

Mysterious source of high energy cosmic rays

The NASA-funded Advanced Thin Ionization Calorimeter (ATIC) balloon instrument has discovered a previously unidentified nearby source of high energy cosmic rays.

The 1,950 kilogram ATIC experiment was designed to be carried to an altitude of about 37,800 metres above Antarctica using a helium-filled balloon. The goal was to study cosmic rays – energetic particles originating from objects in space – that otherwise would be absorbed into the Earth’s atmosphere. Published in this week’s issue of the journal Nature, new results show an unexpected surplus of cosmic ray electrons at very high energy – 300-800 billion electron volts – that must come from a previously unidentified source or from the annihilation of very exotic theoretical particles used to explain dark matter.

"This electron excess cannot be explained by the standard model of cosmic ray origin," says John Wefel, ATIC project principal investigator. "There must be another source relatively near us that is producing these additional particles."

The crew from the Columbia Scientific Balloon Facility prepares to launch the Advanced Thin Ionization Calorimeter (ATIC) experiment from McMurdo Station, Antarctica. Image: NASA.

According to the research, this source would need to be within about 3,000 light years of the Sun. But because of their nature, charged particles are deflected in the galactic magnetic field between wherever they originate and when they are detected at the Earth. "While we do measure the arrival direction, it is not connected to the source location because of bending and scattering in the magnetic field," Wefel tells Astronomy Now.

The source of the cosmic rays could be an exotic object such as a pulsar, mini-quasar, supernova remnant or an intermediate mass black hole. "There are new objects and sources being discovered every day and week," says Wefel. "The ones we know about now do not seem to be able to do the job, but maybe next month one will be found to explain our excess electron data. But since we do not yet see such a source, maybe the alternate explanation – dark matter annihilation – should be considered."

Dark matter is thought to comprise around 23 percent of the Universe’s energy density, while ‘normal’ matter comprises just four percent. Dark energy, which is thought to play a dominant role in the expansion of the Universe, makes up 73 percent. The nature of dark matter is not understood, but its presence can be inferred from the gravitational effects it imposes on visible matter, such as distorting galaxy structure and influencing their rotation speeds. Several theories that describe how gravity works at very small, quantum distances predict exotic particles that could be good dark matter candidates.

"The annihilation of these exotic particles with each other would produce normal particles such as electrons, positrons, protons and antiprotons that can be observed by scientists," says Eun-Suk Seo, ATIC lead at the University of Maryland. "These results may be the first indication of a very interesting object near our Solar System waiting to be studied by other instruments," adds Wefel.

The science team are hoping that there will be new and continuing searches to try to locate a nearby source that can explain the data. "But, we also need to study the exact shape of this feature in more detail to see if it really does have the tell-tale shape expected for dark matter annihilation. That is the on-going experimental challenge," says Wefel.

from:http://astronomynow.com/081121Mysterioussourceofhighenergycosmicrays.html

Planet found orbiting dangerously close to red giant

A new planet found orbiting a red giant star at a distance of just 0.6 AU may shed new light on how aging stars influence nearby planets before they are consumed.

The new exoplanet is around six times the mass of Jupiter and orbits its dying star – HD 102272 – at a distance closer than Venus is to our Sun. The discovery was made by a team of astronomers from Penn State and Nicolaus Copernicus University in Poland using the Hobby-Eberly Telescope of McDonald Observatory in southwestern Texas. By using the telescope’s spectrograph, the astronomers observed patterns in the spectral lines of the light radiating from HD 102272 that represent the fingerprint of a star that is moving alternately toward and away from Earth as it wobbles in space in response to the gravitational pull of an orbiting planet. The specific pattern of these shifts allowed the scientists to determine that at least one planet, and possibly even two, orbit the star. If the second planet exists, the system would become the first multi-planet system discovered around a red giant star.

“If real, the second planet has a very eccentric (e=0.68) orbit with a semi-major axis of 1.6 AU,” team member Professor Alexander Wolszczan tells Astronomy Now. Wolszczan is also the discoverer of the very first planets found outside our Solar System over 15 years ago.

The Hobby-Eberly telescope is located at the McDonald Observatory in far West Texas, which has the darkest skies of any major observatory in the continental United States. Image: Marty Harris/McDonald Obs./UT-Austin.

The team hope that the intriguing system will shed light on the ways in which aging stars can influence nearby planets, although it is already well known that stars of about 0.5-8 solar masses swell and expand towards the end of their lifetimes, possibly swallowing up nearby planets. A similar fate is destined for the Earth in a few billion years time.

“The star is twice as massive as the Sun, meaning that it's been evolving much faster,” says Wolszczan. “Possibly, it will engulf the planet in less than ~100 million years, when it rapidly expands after helium ignition”. From the perilously close distance of 0.6 AU the steadily expanding giant would appear in the planets' alien skies as a huge, reddish disc that is more than 16 times larger than the face of Earth's full Moon appears to us.

“Just like with our planets, the one out there is not much younger than the star, which may currently be at, say, no more than 1.5 billion years,” says Wolszczan. “Detecting planets like that tells us about long-term survival of planetary systems around evolving stars and chances of life to cope with the process or, maybe, even start over, since habitable zones move away and expand as a red giant evolves in time.” Indeed, when our own Sun swells into a red giant, there is the possibility that Jupiter’s icy satellite Europa may fall into the sought after habitable zone. Currently shrouded by an icy shell but possibly hiding an ocean beneath, if it were to exist closer to the Sun, it might become a warm ocean world that could possibly support life.

Wolszczan and colleagues hope that the discovery will teach them about the evolution of planets orbiting extremely close to a red giant star, and what causes planets to avoid forming too close to such a monster. “Although the planet we discovered conceivably could be closer to the star without being harmed by it, there appears to be a zone of avoidance around such stars,” explains Wolszczan. “Our discovery pushes it back to about 0.6 AU, which is the size of the new planet's orbit. It is important to find out why planets don't want to get any closer to stars, so one of our next steps is to try to figure out why this zone of avoidance exists and whether it occurs around all red giant stars.”

HD 102272 is located 1,200 light-years from the Earth in the constellation Leo

from: http://astronomynow.com/081120Planetfoundorbitingdangerouslyclosetoredgiant.html

Site selection narrows for next Mars lander

Four potential landing sites on Mars have been selected as candidates for the touch-down of NASA’s next roving Mars mission, the Mars Science Laboratory.

Location map of the proposed landing sites of the MSL (white labels) compared with the locations of previous Mars missions (marked in yellow). The MSL site selection has now been narrowed to Eberswalde, Holden, Gale Crater and Mawrth Vallis. Image: NASA/JPL.

Three other sites were eliminated in this round and the winning site will be announced next summer, after further evaluation of observations made by Mars orbiters have been made to assess the scientific value and safety risks of the proposed sites. In the running are locations known as Eberswalde, located in an ancient river delta and thought to contain clay minerals that might contain evidence for the carbon chemistry crucial for life; Gale crater, which sports a five kilometre high mountain of layered materials that would provide a record from environments that produced clay deposits near the bottom to later environments that produced sulfate deposits partway up; Holden crater, which bears witness to gullies carved by running water which deposited sediments and clays in lake beds; and Mawrth Valley, a flood channel on the mysterious boundary that separates the northern lowlands from the southern highlands of Mars.

"All four of these sites would be great places to use our roving
laboratory to study the processes and history of early Martian environments and whether any of these environments were capable of supporting microbial life and its preservation as biosignatures," says John Grotzinger, Mars Science Laboratory project scientist.

Several of the sites had been proposed for past missions such as the Mars Exploration Rovers (MERs) Spirit and Opportunity, but were ruled out as too hazardous for the capabilities of those rovers. The Mars Science Laboratory (MSL), however, has improved features that have opened up more areas for exploration. For example, it is larger and more robust than the MERs and is powered by nuclear fuel, allowing it to operate year round without the need for continuous solar power.

The Mars Science Laboratory will be winched down to the Martian surface by a sky crane. Image: NASA/JPL.

The rover will be lowered to the Martian surface via a new ‘skycrane’ technology, similar to how helicopters maneuver large objects through terrestrial skies. This method can accommodate more slope than the airbag method used for Spirit and Opportunity, and can be adjusted last minute to avoid any potentially hazardous boulders, for example. The target landing area is also considerably reduced from a safe area of about 70 kilometres for the MERs to a landing ellipse of just 20 kilometres for MSL.

"Landing on Mars always is a risky balance between science and engineering. The safest sites are flat, but the spectacular geology is generally where there are ups and downs, such as hills and canyons. That's why we have engineered this spacecraft to make more sites qualify as safe," says MSL mission manager Michael Watkins. "This will be the first spacecraft that can adjust its course as it descends through the Martian atmosphere, responding to variability in the atmosphere. This ability to land in much smaller areas than previous missions, plus capabilities to land at higher elevations and drive father, allows us to consider more places the scientists want to explore."

The mission plan calls for the rover to spend a full Martian year (23 months) examining the environment with a diverse payload of tools. The primary goals of the mission will be to characterise the local geology of the landing site and to determine whether life ever arose on the red planet. It will also characterise the climate of Mars and help prepare for human exploration. In order to fulfill these goals, MSL will complete a series of science objectives, such as determining an inventory of organic material and the chemical building blocks for life, and identifying features that might represent the effects of biological processes. MSL will also interpret the processes that have formed or modified rocks and soils at the landing site and surrounding area. The atmospheric measurements will help to assess the present state, distribution and cycling of water and carbon in the planet, and to help prepare for human visitors MSL will determine the nature and amount of radiation received on the Martian surface.

The Mars Science Laboratory will be much larger than previous Mars rovers Spirit and Opportunity. Image: NASA/JPL.

MSL is currently scheduled for launch in September 2009, arriving at the red planet in the summer of 2010. More information about the mission can be found in the Astronomy Now 2009 Yearbook, on sale now.

from:http://astronomynow.com/081120SiteselectionnarrowsfornextMarslander.html

Synchronised observations catch flares from Sagittarius A*

Simultaneous observations made with the VLT and APEX telescopes have revealed the nature of four violent flares emanating from the centre of our Milky Way Galaxy.

Astronomers used ESO’s Very Large Telescope (VLT) and the Atacama Pathfinder Experiment (APEX) to study the region around the Milky Way’s black hole, known as Sagittarius A*, at near-infrared and sub-millimetre wavelengths respectively. Sagittarius A* is a supermassive black hole lurking at the centre of the Milky Way, and boasts a mass of about four million times that of the Sun. Emission from the galactic monster is thought to come from gas thrown off by proximal stars via a strong stellar wind, which then orbits and falls into the jaws of the black hole. Around four to six flares are observed from Sagittarius A* at infrared wavelengths every day.

Colour composite image of the central region of our Milky Way galaxy, about 26,000 light years from Earth. Giant clouds of gas and dust are shown in blue, as detected by the LABOCA instrument on the APEX telescope at sub-millimetre wavelengths. The image also contains near-infrared data from the 2MASS project at K-band (in red), H-band (in green), and J-band (in blue). The image shows a region approximately 100 light-years wide. Image: ESO/APEX/2MASS/A. Eckart et al.

"Only for this one object can our current telescopes detect these relatively faint flares from material orbiting just outside the event horizon," says Frederick Baganoff of the Massachusetts Institute of Technology (MIT). The event horizon marks the boundary beyond which no matter or radiation can escape the gravitational field of the black hole. While supermassive black holes are thought to exist in all galaxies, Sagittarius A* is the nearest one that astronomers can study in such detail.

Making the simultaneous observations required careful planning between teams at the two locations, and is the first time that astronomers have caught a flare by synchronising their observations in this way. "Observations like this, over a range of wavelengths, are really the only way to understand what's going on close to the black hole," says lead astronomer Andreas Eckart of the University of Cologne.

Over a period of six hours the VLT team detected extremely variable emission at infrared wavelengths, with four major flares erupting from Sagittarius A* in that time. The sub-millimetre wavelength results also showed flares, but crucially, they occurred about one and a half hours after the infrared flares. The astronomers put this down to the fact that the clouds of gas that are emitting the flares are expanding rapidly at rates of five million kilometres per hour. This expansion causes changes in the character of the emission over time, resulting in the time delay between the infrared and sub-millimetre flares.

Artist impression of a bright blob of gas in the disc of material surrounding the black hole in the centre of our Galaxy, Sagittarius A* and responsible for the flares detected in this study. As the blob orbits the black hole, it is stretched out, and this expansion over time causes the delay between flares being detected at near-infrared wavelengths (with the VLT) and at sub-millimetre wavelengths (with APEX). Image: ESO/L. Calçada.

The speed of the expansion, while fast, is actually only 0.5 percent of the speed of light, and provides more insight into the nature and cause of the flares. In order to escape from the immensely strong gravity that surrounds the black hole, the gas would have to be travelling at half the speed of light – 100 times faster than that detected – and so the researchers conclude that the gas cannot be streaming out in a jet from the black hole itself. Instead, they suspect that a ‘blob’ of gas orbiting close to the black hole is being stretched out and this is causing the expansion, and therefore the time delay between flares being detected by the VLT and APEX.

By simultaneously carrying out observations at different wavelengths, the astronomers have created a powerful tool to reveal the nature of flares emitted in the regions of black holes. As a next step, Eckart and his team hope to make further observations that will allow them to develop their proposed model for flare emission, and discover more about this mysterious region at the centre of our Galaxy.

from:http://astronomynow.com/081119synchronisedobservationscatchflaresfromSagA.html

1000 telescopes for schools

In an ambitious project led by the Society for Popular Astronomy (SPA), the Science Facilities and Technology Council (STFC) and the Royal Astronomical Society (RAS), 1000 telescopes will be donated to secondary schools in the UK to inspire the next generation of astronomers throughout the International Year of Astronomy.

The landmark project, Telescopes for Schools, is just one part of the global effort to celebrate the International Year of Astronomy (IYA 2009), which commemorates the 400th anniversary of Galileo's first use of the telescope for astronomy, as well as the 40th anniversary of the first Moon landings. An English astronomer, Thomas Harriott, also first used a telescope to observe the Moon 400 years ago.

Four centuries later, the Telescopes for Schools project aims to inspire another generation of astronomers by enthusing pupils in subjects like physics and mathematics. "We think every pupil should have the chance to look through a telescope, an experience they will remember for the rest of their lives," says SPA President Helen Walker. "The UK has a flourishing community of amateur and professional astronomers. Through Telescopes for Schools they can share their enthusiasm with our young people."

Children at the Glasgow Science Centre enjoying a first look through one of 1000 free telescopes set to be delivered to UK schools. Image: International Year of Astronomy 2009, UK.

Schools can apply for one of the 70mm refractor telescopes via the SPA’s Moonwatch website at www.popastro.com/moonwatch, designed to support the project. The participating schools will also receive a DVD with clips explaining how to use their telescope and what they can look at, as well as interviews with enthusiastic astronomers and additional support materials for teachers. The schools are encouraged to find a local astronomer to help them use the telescope, but if the school does not know any local astronomers, the SPA has undertaken to try and find one from the communities of amateur and professional astronomers.

"The UK is a world leader in astronomy and we aim to use IYA 2009 to provide a launch pad to stimulate public interest in astronomy and the night sky and to encourage the take-up of science and technology in schools,” says Professor Ian Robson, who leads the IYA 2009 activities in the UK. “The launch of this project is tremendously exciting and I look forward to the excitement it will generate."

The Telescopes for Schools project will allow students to follow in Galileo's and Harriott’s footsteps and look at craters on the Moon or the satellites of Jupiter, and many other night sky objects including the rings of Saturn, bright clouds of gas and dust (nebulae), star clusters and even other galaxies. "The telescopes will give you a better understanding of the wider Universe," says RAS President Professor Andy Fabian

from:http://astronomynow.com/0811191000telescopesforschools.html

Scientists dive deeper into Mars’ watery past

An international team of scientists working with data gleaned from Mars Odyssey’s Gamma Ray Spectrometer report new evidence for the controversial idea that oceans once covered as much as one-third of ancient Mars.

Today, on the Earth, oceans occupy around two-thirds of our planet, but all of the Martian oceans have long since dried up. Although the fleet of spacecraft and landers visiting Mars since the 1970s have demonstrated widespread evidence for a watery past, planetary scientists find it considerably challenging trying to identify ancient ‘shorelines’ on Mars, since they look a lot different to those we are more familiar with on Earth. For example, Earth's well-defined coastal shorelines are largely a direct result of powerful tides caused by gravitational interaction between Earth and the Moon, but Mars lacks a sizable moon that could have exerted such a force on the planet. In addition, that lakes or seas on Mars could have formed from giant debris flows and liquefied sediments, and Martian oceans may have been ice-covered, which would prevent any wave action and subsequent erosion of the coastline.

This 3D map superimposes gamma ray data from Mars Odyssey's GRS onto topographic data from the laser altimeter onboard the Mars Global Surveyor. The red arrow indicates the shield volcanoes of Elysium rise in northern Mars. Blue-to-violet colours mark areas poor in potassium and red-to-yellow colours mark potassium-rich sedimentary deposits in the lowlands below the Mars Pathfinder landing site (PF) and Viking 1 landing site (V1).

In the new study, lead by University of Arizona planetary geologist James Dohm, the shorelines are based on past investigations using topographic measurements. The team used data from NASA’s Mars Odyssey spacecraft, in particular the Gamma Ray Spectrometer (GRS), which is capable of detecting elements buried as much as 33 centimetres below the surface of Mars by the gamma rays they emit, to delineate the ancient shorelines on Mars. The capability of the GRS was previously demonstrated in the ground-breaking discovery of water-ice near the surface throughout much of high-latitude Mars in 2002.

"We compared GRS data on potassium, thorium and iron above and below a shoreline believed to mark an ancient ocean that covered a third of Mars' surface, and an inner shoreline believed to mark a younger, smaller ocean," says Dohm. "Our investigation posed the question: Might we see a greater concentration of these elements within the ancient shorelines because water and rock containing the elements moved from the highlands to the lowlands, where they eventually ponded as large water bodies?"

Results from Mars Odyssey and other spacecraft suggest that past watery conditions likely leached, transported and concentrated such elements as potassium, thorium and iron into the lowlands. The team found that the potassium-thorium-iron enriched areas occur below the older and younger ocean boundaries with respect to the entire region. "In other words, GRS elemental information is consistent with the ancient aqueous activity documented in the literature, such as the transferral of volatiles and rock materials to the northern plains and the formation of lakes and oceans in the northern plains, which includes marine deposits that either remained unburied and/or are exposed by erosion and deformation," Dohm tells Astronomy Now. "The regions below and above the two shoreline boundaries are like cookie cutouts that can be compared to the regions above the boundaries, as well as the total region."

An illustration showing the location of the Tharsis volcanic region and Valles Marineris in the context of the hypothesized larger, ancient ocean and smaller, more recent ocean in Mars' northern lowland planes. It is argued that Tharsis volcanism unleashed great floods that carved large outflow channels and deposited sediment carried from the southern cratered highlands to the northern lowland plains, where water formed lakes and oceans and changed climate for thousands of years.

The research team liken the younger inner shoreline to an ocean ten times the size of our Mediterranean Sea that existed on the northern plains of Mars a few billion years ago, and think that the larger, more ancient shoreline that covered a third of Mars held an ocean about 20 times the size of the Mediterranean.

Understanding how and when water existed on Mars is crucial in determining the habitability of the red planet, since water is a vital ingredient for life as we know it. The debate as to the possible existence of ancient Martian oceans marked by shorelines has been a colourful area of discussion for over twenty years. A trigger for global oceans, according to a report by Professor Victor Baker and colleagues at the University of Arizona Lunar and Planetary Laboratory, is that erupting magma caused extreme heating, and therefore resulted in vast areas of ice melting and unleashing floods that ponded in the northern lowlands of Mars, forming seas and lakes.

“Several investigators hypothesize that before the magmatic-driven release, the ice begins to melt and carbon dioxide gases begin to build below impermeable ice somewhat like a lid - think of shaking a pop can,” explains Dohm. “Eventually, the carbon dixoide-charged water is released catastrophically in floods of enormous magnitudes.”

The latest analysis of GRS data adds key information to the long-standing oceans on Mars controversy. "But the debate is likely to continue well into the future, perhaps even when scientists can finally walk the Martian surface with instruments in hand, with a network of smarter spaceborne, airborne and ground-based robotic systems in their midst,” says Dohm

from: http://astronomynow.com/081119scientistsdivedeeperintoMarswaterypast.html

XMM and Integral unveil magnetar environment

X-ray and gamma ray data from ESA's XMM-Newton and Integral orbiting observatories have been used to make the first tests of the physical processes that define magnetars, an unusual class of neutron star with immense magnetic fields.

Neutron stars are the remnants of stars 10-50 times more massive than our Sun that have collapsed in on themselves such that the equivalent mass of our Sun is concentrated into a sphere just 20 kilometres in diameter. Neutron stars are also defined by their extremely fast rotation and ultra-strong magnetic field. Magnetars are a sub-class of neutron star that boast magnetic fields a thousand times stronger than that of ordinary neutron stars, and in total, astronomers know of just 15 such magnetic powerhouses.

X-ray and gamma ray data from ESA’s XMM-Newton and Integral orbiting observatories have been used to test, for the first time, the physical processes thought to lie behind the emission of magnetars, an atypical class of neutron stars with ultra-strong magnetic fields. Image: 2008 Sky & Telescope/Gregg Dinderman.

A magnetar’s magnetic field is so great that it is thought to be capable of twisting its own stellar crust, producing a current in the form of an electron cloud which flows around the star. These currents interact with the radiation coming from the stellar surface, producing X-rays which are observed by satellites such as XMM-Newton and Integral.

Until now, the electron clouds around magnetars were just a theoretical prediction, since it is not possible to produce such ultra-strong magnetic fields in laboratories on Earth. Dr Nanda Rea from the University of Amsterdam and colleagues have now demonstrated the presence of electron clouds around the whole set of known magnetars by building a theoretical code which takes into account the effect of these clouds, and then applying this code to X-ray and low energy gamma ray observations from XMM-Newton and Integral of all 15 magnetars.

“This model could perfectly fit all the data on these objects, resulting in a measurement of the electron density and temperature in the magnetosphere of these big magnets,” Rea tells Astronomy Now. “Their presence demonstrate that indeed the theoretical prediction of a twisted magnetosphere is correct, and that their peculiar X-ray emission (with respect to normal neutron stars) is in great part due to these electron clouds 1000 times denser than in normal neutron stars.”

The results have established an important link between an observed phenomenon and an actual physical process, and the team is now working hard to develop and test more detailed models to fully understand the behaviour of matter under the influence of such strong magnetic fields
from:http://astronomynow.com/081117XMMandIntegralunveilmagnetarenvironment.html

Scientists dive deeper into Mars’ watery past

An international team of scientists working with data gleaned from Mars Odyssey’s Gamma Ray Spectrometer report new evidence for the controversial idea that oceans once covered as much as one-third of ancient Mars.

Today, on the Earth, oceans occupy around two-thirds of our planet, but all of the Martian oceans have long since dried up. Although the fleet of spacecraft and landers visiting Mars since the 1970s have demonstrated widespread evidence for a watery past, planetary scientists find it considerably challenging trying to identify ancient ‘shorelines’ on Mars, since they look a lot different to those we are more familiar with on Earth. For example, Earth's well-defined coastal shorelines are largely a direct result of powerful tides caused by gravitational interaction between Earth and the Moon, but Mars lacks a sizable moon that could have exerted such a force on the planet. In addition, that lakes or seas on Mars could have formed from giant debris flows and liquefied sediments, and Martian oceans may have been ice-covered, which would prevent any wave action and subsequent erosion of the coastline.

This 3D map superimposes gamma ray data from Mars Odyssey's GRS onto topographic data from the laser altimeter onboard the Mars Global Surveyor. The red arrow indicates the shield volcanoes of Elysium rise in northern Mars. Blue-to-violet colours mark areas poor in potassium and red-to-yellow colours mark potassium-rich sedimentary deposits in the lowlands below the Mars Pathfinder landing site (PF) and Viking 1 landing site (V1).

In the new study, lead by University of Arizona planetary geologist James Dohm, the shorelines are based on past investigations using topographic measurements. The team used data from NASA’s Mars Odyssey spacecraft, in particular the Gamma Ray Spectrometer (GRS), which is capable of detecting elements buried as much as 33 centimetres below the surface of Mars by the gamma rays they emit, to delineate the ancient shorelines on Mars. The capability of the GRS was previously demonstrated in the ground-breaking discovery of water-ice near the surface throughout much of high-latitude Mars in 2002.

"We compared GRS data on potassium, thorium and iron above and below a shoreline believed to mark an ancient ocean that covered a third of Mars' surface, and an inner shoreline believed to mark a younger, smaller ocean," says Dohm. "Our investigation posed the question: Might we see a greater concentration of these elements within the ancient shorelines because water and rock containing the elements moved from the highlands to the lowlands, where they eventually ponded as large water bodies?"

Results from Mars Odyssey and other spacecraft suggest that past watery conditions likely leached, transported and concentrated such elements as potassium, thorium and iron into the lowlands. The team found that the potassium-thorium-iron enriched areas occur below the older and younger ocean boundaries with respect to the entire region. "In other words, GRS elemental information is consistent with the ancient aqueous activity documented in the literature, such as the transferral of volatiles and rock materials to the northern plains and the formation of lakes and oceans in the northern plains, which includes marine deposits that either remained unburied and/or are exposed by erosion and deformation," Dohm tells Astronomy Now. "The regions below and above the two shoreline boundaries are like cookie cutouts that can be compared to the regions above the boundaries, as well as the total region."

An illustration showing the location of the Tharsis volcanic region and Valles Marineris in the context of the hypothesized larger, ancient ocean and smaller, more recent ocean in Mars' northern lowland planes. It is argued that Tharsis volcanism unleashed great floods that carved large outflow channels and deposited sediment carried from the southern cratered highlands to the northern lowland plains, where water formed lakes and oceans and changed climate for thousands of years.

The research team liken the younger inner shoreline to an ocean ten times the size of our Mediterranean Sea that existed on the northern plains of Mars a few billion years ago, and think that the larger, more ancient shoreline that covered a third of Mars held an ocean about 20 times the size of the Mediterranean.

Understanding how and when water existed on Mars is crucial in determining the habitability of the red planet, since water is a vital ingredient for life as we know it. The debate as to the possible existence of ancient Martian oceans marked by shorelines has been a colourful area of discussion for over twenty years. A trigger for global oceans, according to a report by Professor Victor Baker and colleagues at the University of Arizona Lunar and Planetary Laboratory, is that erupting magma caused extreme heating, and therefore resulted in vast areas of ice melting and unleashing floods that ponded in the northern lowlands of Mars, forming seas and lakes.

“Several investigators hypothesize that before the magmatic-driven release, the ice begins to melt and carbon dioxide gases begin to build below impermeable ice somewhat like a lid - think of shaking a pop can,” explains Dohm. “Eventually, the carbon dixoide-charged water is released catastrophically in floods of enormous magnitudes.”

The latest analysis of GRS data adds key information to the long-standing oceans on Mars controversy. "But the debate is likely to continue well into the future, perhaps even when scientists can finally walk the Martian surface with instruments in hand, with a network of smarter spaceborne, airborne and ground-based robotic systems in their midst,” says Dohm
from:http://astronomynow.com/081119scientistsdivedeeperintoMarswaterypast.html

Planet family photographed around normal star

Astronomers using the Gemini North telescope and W.M. Keck Observatory on Hawaii's Mauna Kea have obtained the first images of a multi-planet system around a normal star.

"We finally have an actual image of an entire system. This is a milestone in the search and characterisation of planetary systems around stars," says Bruce Macintosh of the Lawrence Livermore National Laboratory.

Gemini Observatory discovery image showing two of the three confirmed planets indicated as b and c. b is the ~7 Jupiter-mass planet orbiting at about 70 AU; c is the ~10 Jupiter-mass planet orbiting the star at about 40 AU. Due to the brightness of the central star, it has been blocked and appears blank in this image to increase visibility of the planets. Image: Gemini Observatory

The new solar system orbits a dusty young star known as HR 8799, which is 140 light years away and about 1.5 times the size of our Sun and five times more luminous. Three planets, two roughly ten times and one seven times the mass of Jupiter orbit the star at distances equivalent to 24, 37 and 67 times the Earth-Sun separation (1 astronomical unit, or AU). Moreover, the size of the planets decreases with distance from the parent star, much like the giant planets do in our own Solar System. The furthest planet in the system orbits just inside a disc of dusty debris, similar to that produced by the comets of the Kuiper belt of our Solar System, just beyond the orbit of Neptune at 30 AU. The discovery team have commented that the system seems to be a scaled up version of our Solar System orbiting a slightly larger and brighter star.

"Seeing these planets directly – separating their light from the star – lets us study them as individuals, and use spectroscopy to study their properties, like temperature or composition," says Macintosh. "We can see some evidence for complex cloud structure in their atmosphere and soon we'll be able to get spectra, and say something about composition."

Using the Gemini North telescopes, the international team made the initial discovery of two of the planets in the planetary system in October 2007. Follow-up observations with the Keck II telescope confirmed the discovery and discerned a third planet orbiting even closer to the star. In both cases, adaptive optics technology – with a resolution of 0.4 seconds of arc – was used to correct in real-time for atmospheric turbulence to obtain these historic infrared images of an extrasolar multiple planet system.

Naked eye and binocular finder charts for HR 8799. The host star is faintly visible to the naked eye, but only to those who live well away from bright city lights or have a small telescope or even binoculars. Image: Gemini Observatory Illustration by Stephen James O'Meara.

"Until now, when astronomers discover new planets around a star, all we see are wiggly lines on a graph of the star's velocity or brightness. Now we have an actual picture showing the planets themselves, and that makes things very interesting," says Macintosh.

The host star is a bright, blue, A-type star, which are often ignored in ground and space-based direct imaging surveys since they offer a less favorable contrast between a bright star and a faint planet. But their advantage over the Sun is that they can retain heavy discs of planet-making material and therefore form more massive planets at wider separations that are easier to detect. Indeed, as Ben Zuckerman of UCLA comments: "HR 8799's dust disc stands out as one of the most massive in orbit around any star within 300 light years of Earth." HR 8799 is also young – less than 100 million years old – which means its planets are still glowing with heat from their formation.

The observations of HR 8799 form part of a larger survey of 80 such young, dusty and massive stars located in the solar neighborhood. This discovery was made after observing only a few stars, which may lead to the conclusion that Jupiter-mass planets at separations similar to the giant planets of our Solar System are frequent around stars only a bit more massive than the Sun. What is certain is that HR 8799's planetary system will be studied in great detail in the years to come, and will undoubtedly be a prime target for next-generation exoplanet-finding instruments and dedicated space missions. Ultimately, astronomers are working towards images and spectroscopic studies of truly Earthlike planets.

Artist impression of the multiple planet system, that hosts three planets of 10, 10 and 7 times Jupiter mass. Image: Gemini Observatory Artwork by Lynette Cook.

"After all these years, it's amazing to have a picture showing not one but three planets. The discovery of the HR 8799 system is a crucial step on the road to the ultimate detection of another Earth," says Macintosh. "I think there's a very high probability that there are more planets in the system that we can't detect yet. One of the things that distinguishes this system from most of the extrasolar planets that are already known is that HR 8799 has its giant planets in the outer parts – like our solar system does – and so has 'room' for smaller terrestrial planets – far beyond our current ability to see – in the inner parts."

The article is published in the 13 November 2008 issue of Science Express
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Hubble images exoplanet

Using the Hubble Space Telescope, a team of astronomers has taken an image of a planet around the star Fomalhaut. It is the first such image of an exoplanet taken in visible wavelengths. The results have been published today in the journal Science.

Fomalhaut lies 25 light years away in the constellation Piscis Austrinus, the Southern Fish, and is surrounded by a striking debris ring. The planet, Fomalhaut b, resides inside this ring and orbits the star at a distance of 119 astronomical units (an astronomical unit, AU, being the distance between the Earth and the Sun). In other words, Fomalhaut b orbits its star at nearly four times the distance that Neptune does from the Sun. Previous Hubble images of the debris ring have shown it to bear an uncanny resemblance to the ‘eye of Sauron’ from the Lord of the Rings films.

This 2006 Hubble Space Telescope optical image shows the belt of dust and debris (bright oval) surrounding the star Fomalhaut and the planet (inset) that orbits the star every 872 years and sculpts the inner edge of the belt. A coronagraph on the Advanced Camera for Surveys blocks out the light of the star (centre), which is 100 million times brighter than the planet. Image: Paul Kalas, UC Berkeley/NASA/ESA.

Professor Paul Kalas of the University of California, Berkeley, has been studying the Fomalhaut system for 15 years. He first imaged Fomalhaut’s debris belt in 2005 using Hubble’s Advanced Camera for Surveys, and quickly noticed that the belt had a sharp, inner edge. "The gravity of Fomalhaut b is the key reason that the vast dust belt surrounding Fomalhaut is cleanly sculpted into a ring,” he says. This is similar to the way that Saturn’s rings are kept trim by the activity of its moons. It has taken three years to obtain two images of Fomalhaut b. But with these images, Kalas has been able to show that the planet has an annual orbit of 872 years, correlating exactly with its distance from the star.

And it gets even more interesting. Kalas and his team detected a dip in the planet’s brightness by half a stellar magnitude in the time that the two images were taken. What could be the explanation? Hot gas from the debris ring around the planet, and a hot outer atmosphere heated by convective cells, have both been touted as explanations. But could the dip also be due to a moon passing in front of the planet? “That would be one exotic possibility that requires future observations to either confirm the idea, or exclude it,” Kalas says
from:http://astronomynow.com/081114Hubbleimagesexoplanet.html

Exclusive Interview: Richard Garriott:Space tourist

Richard Garriott, a significant figure in the video game industry, recently established himself as a self-funded space tourist, spending ten days onboard the International Space Station (ISS) in October. Astronomy Now’s Website Editor Emily Baldwin spoke to Garriott about the highs and lows of his space station experiences, and his thoughts on the future of space tourism.

What inspired you to want to take on the challenge of training as an astronaut and to go into space?
I think everybody, at some time in their life, imagines they might want to travel into space, so in that way I don’t think I was any different to anyone else. What was different for me is not only was my father an astronaut [Owen Garriott] which made it seem more practical, but also, when I was a teenager, a NASA physician told me I would not be eligible to be a NASA astronaut because of my poor eyesight. For me, instead of making the dream go away, it made me think “wait a minute, you can’t tell me I’m not allowed to go into space” and so I worked ever since then to privatise space and find a way for private citizens to get there, and of course most especially me.

How long did you have to train for, and what preparations did you have to make in order to be ready for the trip?
My training has been most of 2008, and my training here in Russia has mostly been what you might consider intellectual training. That is, learning all the systems onboard the Soyuz and the Space Station to make sure I could operate safely and independently, as well as practice all the experiments I wanted to do. But even before that I had medical preparations to do, where you have to learn about the physiological challenges of living in space, which are considerably greater than what people might expect.

Did you encounter any difficulties with your health that you weren’t expecting?
There were some challenges that I didn’t realise in advance how significant they would be. For example, about 80 percent of people who go into space get what is called space adaptation sickness, which a lot of people think of as motion sickness. I actually didn’t have that because the Russians have a very nice preparation scheme for acclimatising yourself to potential motion sickness that helped me. But on the other hand there is another effect that occurs, called a fluid shift, that when you live in zero-g it kind of feels like you’re hanging upside down on monkey bars. And when you hang upside down for say five minutes you can feel the extra fluid pressure in your head but it doesn’t really bother you. But if you can imagine doing that for five hours or five days you can imagine that it can become particularly uncomfortable. And so for the first five days I felt like I had a head cold, and I really didn’t feel too comfortable. Also your stomach and intestines basically shut down when you’re in space and so you feel a little sick and just not really yourself. A lot of people describe those effects as fairly normal when in space.

What was your role in the mission?
I really had three main areas. One was to prove or demonstrate that as a private astronaut I could still contribute scientifically and commercially like a career astronaut. So I did a variety of experiments and one which was probably the most scientifically interesting was called Protein Crystal Growth where I grew a very large number of protein crystals which are now being studied on the ground and which I believe will contribute significantly to the understanding of this very important science that really stands a good chance of advancing the medical field in a very important way. [The proteins have important cellular functions that are usually associated with common human diseases, and the weightless environment of space allows large crystals to grow, enabling researchers to learn more about their molecular structure and how they can be used to develop drugs to combat disease]. I also spent a good deal of my time doing second generation experiments. Since my father was an astronaut and took photos of the Earth, I worked with a group called the Nature Conservancy to study those NASA photographs to find places I could or should photograph myself from space to showcase how the Earth has changed in 35 years in one generation of space flight. And then there were educational activities. In fact, I spent almost 30 percent of my time on orbit doing educational experiments and answering educational questions. I worked with the British National Space Centre as well as the Challenger centres and did experiments for the teachers and the students. I also connected by ham radio [amateur radio] to students all around the globe. And finally I did what we call 'personal symbolic activities', in particular I did an art show on orbit and I even created a science fiction movie.

Garriott used some of his personal time to put on an art show.

Image: www.richardinspace.com.

You also ran a competition for children to design some experiments for you to carry out in space. What were some of the things they came up with?
We had a contest with a variety of different age groups. The oldest kids proposed future plans to take advantage of space that weren’t necessarily things I could do in a short duration orbit, but they were designing things like hotels and buildings in orbit that might accommodate larger numbers of people. And for the slightly younger kids they had me doing experiments like what happens in your daily routines, like when you brush your teeth, wash your hair, rinse your mouth out and so on. Basically, how can you rinse your mouth out without a sink to spit into, for example? And so they had me doing some experiments relating to life in space. The very youngest kids asked me very insightful questions that were actually quite tricky to answer, like is it hot or cold in space? Of course space is a vacuum and so as such has no inherent temperature of its own. Its temperature is actually the measure of energy or motion of the molecules of a medium like the surface you might touch. So in space if you’re in a shadow like behind the space station or behind the Earth it can get very cold very quickly as you radiate your heat away, and in the sunlight you absorb that heat and the vacuum around you, which is a great insulator, gets hotter and hotter and you would overheat very quickly. So space really has no temperature but you get cold in the shade and hot in the Sun.

How do things ‘work’ on the space station?
Life is dependant on a number of things onboard the station. For example you have to have electrical power – there are giant solar panels all over it, giant batteries in some of the main areas of the station, and yet what’s interesting is that there’s no voltmeter because it’s all managed from the ground, so it just works and some people on the ground keep an eye on it so you don’t have to. Another thing that’s really important is having enough oxygen. There’s a system that works through electrolysis, these water tanks get brought up and get split into hydrogen and oxygen, and the hydrogen is vented outside and oxygen is brought into the main cabin, but there’s no oxygen gauge. Another thing that’s really important is to get rid of the carbon dioxide, but there’s no carbon dioxide gauge! All these things you can find – you can go to a laptop and bring it up and look at the displays but there’s no really obvious in front of you gauge. Same with temperature – there’s no thermostat on the air conditioning system for example. The systems are incredibly well designed, they just operate themselves, and they’re monitored by the ground and it’s only in the very extreme conditions do they notify the crew and say “hey, there’s something you might need to take a look at.” Otherwise it just works. For example on the few days I spent on Soyuz, it’s designed astoundingly well such that you don’t have to turn on air conditioning or heating, it just works by itself. It’s insulated well enough that it retains its own temperature. Any excess heat is automatically dumped through radiators and you’ve got little heaters that are also operating to make sure things don’t get too cold. And it all just operates automatically without any human interaction.

What was it like when the toilet broke?
Actually they had cured the toilet by the time I got onboard. However, you hear that the most common question kids ask is how do you go to the bathroom in space? But having not been an astronaut before, when I got over here [to Russia] one of the questions I had is how do you go to the bathroom in space? It’s funny, because even amongst astronauts and cosmonauts, one of the most common dinner time conversations is using the bathroom and what parts are easy and what parts are difficult. Liquid collection is really no problem, it’s basically a funnel with a vacuum behind it that you pee into, and the only challenge is how to keep yourself floating away while you’re trying to hold the funnel in front of you. Technically a little challenging but it’s no big deal. On the other hand, dealing with the solid waste is quite a bit more challenging. The method is still basically the same, but you sit on a miniature toilet which is lined with a plastic bag with perforations on the bottom, and there’s a fan below that is there to pull things into the bag. However it doesn’t really work that well, it doesn’t respond in the same way that gravity assists you in getting rid of solid wastes on the Earth. So that is an area that requires additional strategies!

NASA astronaut Greg Chamitoff (left) and Richard Garriott pose for a photo in the Zvezda Service Module of the International Space Station. Image: NASA.

What was the most interesting thing you saw on the Earth

from space?
One was the San Francisco bay area. One of the things that was really striking was still how close to the Earth we were in spite of being as high up as we were [the ISS orbits at an altitude of about 350 kilometres]. As you look to the horizon you can see the blackness of space and the curvature of the Earth, and the thin veil of the atmosphere on top of the Earth, but looking straight down you can still see airports, air plane contrails, the clouds, I could still see all the ship wakes going in and out of the Bay area, I could see the Golden Gate Bridge and the Oakland Bay Bridge, all easily viewable from space. It was interesting to realise how still intimately close you were with the Earth. And you hear how man made objects are difficult to see from space, – at least from low Earth orbit that’s just not true. You can see the Palm islands in Dubai and the New World Islands very easily by eye. You see weather systems in a completely different way because you could see that from horizon to horizon they interact with each other in ways you would not see from the ground. Also you can see the geological interaction of the planet, like plate tectonic movement, – it really does appear like one continuous flowing surface of the Earth. And even how humanity has pretty much inhabited all the fertile areas of the Earth is really quite apparent from viewing it from space.

What was a typical day like for you?
Well, we ignored bed time but apart from that we had a pretty good schedule! We would get up at 5am GMT, we’d spend an hour and a half having breakfast and doing morning hygiene routines and printing out our daily schedule and preparing for work. At 6.30 or 7am we’d start our work day and everyone had independent schedules. The work days were quite full, but we all got together for lunch and dinner, and after dinner was largely our own to do our personal projects which tended to run until midnight or 1am. And then you get a bit of rest before starting again a few hours later!

What were the highs and lows of your trip?
A low point would be on flight day 5 I woke up with a horrific headache that lasted the whole day. There was some debate as to what the cause was but one possibly is that because you sleep in a sleeping bag, and for at least a little bit of the time in that particular night I’d brought my face into the sleeping bag which tends to mean you breathe in and out the same air, so basically I had carbon dioxide poisoning. So I felt really poorly that day. The highlight would probably be my ham radio activities. I talked to over 500 individuals around the globe and had about a dozen contacts with school groups to answer questions. I was also sending lots of slow scan television images down by ham radio and it became very clear early on that people all around the globe were really paying pretty close attention to my flight and observing all the ham radio images I sent down, and were making commentary to me about the images, or how much they were enjoying following along, and getting the chance to talk with me. And I was really very, very moved, especially in the last few days when I spoke to classrooms full of kids, who’d only be online for 30 seconds and would all say “Hi Richard, bye Richard, have a good trip home,” all together. It was really very, very special.

What were launch and re-entry like?
The launch and re-entry of course are both very special times, just like living on the Space Station itself. Launch is very smooth, it doesn’t feel dangerous in any way and it doesn’t overload your body too much. The g-forces went up to about 4.5g but you don’t feel uncomfortable in any way, you just feel like it’s eight minutes of very confident lifting from behind, lifting into the sky by this amazing vehicle that doesn’t shudder or shake or give any indication of the astounding difficulty of reaching space. Re-entry again feels much more confident and comfortable than I expected but the view is really spectacular. When you’re coming in through the upper atmosphere and seeing the heat shield burn off and the plasma outside the window, it’s really astounding. And when the main parachutes open, the whole vehicle is like it’s on the end of very big whip that gets cracked; you get rolled around with some significant jostling, and after that you’re just drifting down quite comfortably under a canopy until you get down to the ground. The vehicle hitting the ground is like a 30mph car crash, but what’s interesting is that you’re in a seat that’s perfectly moulded to your body and it has shock absorbers, so landing’s actually really comfortable. But the vehicle around you takes a significant impact, but really it’s not particularly alarming, it’s just noticeable.

Weather systems can be seen in a totally different way from 380 kilometres above the ground! This is Hurricane Ike, taken by crew onboard the ISS in September. Image: NASA.

How do you think space tourism will be developed in the future, and could we eventually be making trips into space as regularly as 'normal' destination holidays?
The more I’ve learnt about this the more I can break space travel into a few categories. So first there is sub orbital spaceflight which is going to become commercial in the next few years. I believe the ultimate price for those flights will come down to into the tens of thousands of dollars. Which means if you can afford a first class ticket for a vacation across the other side of the planet, you’ll be able to afford instead a flight to space, so a lot of people will be able to take sub orbital space flights. However, the speeds and energies involved to get all the way into orbit and back are considerably more daunting so I don’t think that that’s going to become cheaper than millions of dollars any time soon. So therefore it will either stay in the hands of wealthy individuals, or what I hope happens and this is what I’m hoping to work towards, is that I can demonstrate that there are things to do in orbit that are worth putting people there for, and not because they are sponsored by the government. For example, we spend a lot of money putting someone on an oil rig to bring back oil because oil’s worth it. And as soon as there’s things to do in space that are worth doing then that will take a lot of people into space, not just as vacation but for people to live and work.

What advice would you give a school age student wanting to become an astronaut?
I would say, to either go privately or to go as a government sponsored professional, the advice is pretty similar. One of the things that made this appropriate for me, in the sense that it allowed me to train and work as a crew member and being accepted as a private flyer by my crew, is that I have a very diverse background. I enjoy subject matter across the board from science to history to math, and that really has been helpful in making my journey successful. That also happens to be important if you want to apply for a job as an astronaut, and it happens to be important if you want to be a successful entrepreneur, which allowed me to afford myself this opportunity to go into space. So for kids, enjoy your classes, enjoy as many different areas of knowledge that you can, pick up as much as you can in as many fields of knowledge as possible. Find something to do that you really love. I’m really lucky I’m doing computer games in my case, which I’m really passionate about and really love, and when you know a subject well enough and are passionate enough about it, you do well at it, and so I think that’s what helped me be successful in this industry and ultimately has taken me into space.

Do you have any plans to make further trips into space?
Of course I do hope I do get to come back, but I believe it will most likely be when I can put a business plan together, so to speak, that will pay for my trip to space rather than coming out of my own pocket. It will be a few years, but as soon as possible.

You can read more about Richard Garriott and his space adventures at: www.richardinspace.com

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