Posted on by Fraser Cain

Next Mars Mission Arrives at the Cape

Workers rolling a case containing parts of the Mars Reconnaissance Orbiter equipment into the Payload Hazardous Servicing Facility. Image credit: NASA. Click to enlarge.
A large spacecraft destined to be Earth’s next robotic emissary to Mars has completed the first leg of its journey, a cargo- plane ride from Colorado to Florida in preparation for an August launch. NASA’s Mars Reconnaissance Orbiter is an important next step in fulfilling NASA’s vision of space exploration and ultimately sending human explorers to Mars and beyond.

The spacecraft’s prime mission will run through 2010. During this period, the project will study Mars’ composition and structure, from atmosphere to underground, in much greater detail than any previous orbiter. It will also evaluate possible sites for future martian landings and will serve as a high-data-rate communications relay for surface missions.

“Great work by a talented team has brought Mars Reconnaissance Orbiter to this milestone in our progress toward a successful mission,” said Jim Graf of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., project manager for the mission.

The spacecraft arrived at Kennedy Space Center’s Shuttle Landing Facility on April 30 aboard a C-17 cargo plane and was taken to the Payload Hazardous Servicing Facility to begin processing. It was built near Denver by Lockheed Martin Space Systems. Launch is scheduled for Aug. 10 at 7:53:58 a.m. EDT (4:53:58 a.m. PDT), at the opening of a two-hour launch window.

The spacecraft will undergo multiple mechanical assembly operations and electrical tests to verify its readiness for launch. A test this month will verify the spacecraft’s ability to communicate through NASA’s Deep Space Network tracking stations. A June test will check the deployment of the spacecraft’s high gain communications antenna. Another major deployment test will check out the spacecraft’s large solar arrays.

In July, the spacecraft will be filled with hydrazine fuel for the “Mars orbit insertion” engine burn, which will be used to reduce the velocity of the spacecraft and place it in orbit around Mars. The fuel also will be used for attitude-control propellant. On July 26 the Mars Reconnaissance Orbiter will be encapsulated in the Atlas V fairing prior to being moved to its launch site on Cape Canaveral Air Force Station.

The Lockheed Martin Atlas V arrived at Cape Canaveral Air Force Station aboard an Antonov cargo plane on March 31 and was taken to the high bay at the Atlas Spaceflight Operations Center. The Atlas booster will be transported in May to the Vertical Integration Facility at Space Launch Complex 41 to be erected. The Centaur upper stage will be transported to that facility for hoisting atop the booster in June.

Prelaunch preparations will include a “wet dress rehearsal” in July, during which the Atlas V will be rolled from the Vertical Integration Facility to the launch pad on its mobile launch platform. The vehicle will be fully fueled with RP-1, liquid hydrogen and liquid oxygen, and the team will perform a simulated countdown. The Atlas V will then be rolled back into the Vertical Integration Facility for final launch preparations.

The Mars Reconnaissance Orbiter will be transported from the Payload Hazardous Servicing Facility at Kennedy Space Center to the Vertical Integration Facility on July 29. It will be hoisted atop the launch vehicle to join the Atlas V for the final phase of launch preparations. The spacecraft is scheduled to undergo a functional test on August 1, followed by a final week of launch vehicle and spacecraft closeouts.

The Mars Reconnaissance Orbiter mission is managed by JPL, a division of the California Institute of Technology, Pasadena, for the NASA Science Mission Directorate, Washington. Lockheed Martin Space Systems is the prime contractor for the project. International Launch Services, a Lockheed Martin joint venture, and Lockheed Martin Space Systems are providing launch services for the mission.

Information about Mars Reconnaissance Orbiter is available online at http://marsprogram.jpl.nasa.gov/mro.

Original Source: NASA/JPL News Release

Posted on by Fraser Cain

Return to Flight Delayed to July

Crew of STS-114, practicing for their upcoming launch. Image credit: NASA. Click to enlarge.
NASA announced today July 13 to 31 is the new launch planning window for the Space Shuttle Discovery mission. The new window gives the agency time to do additional work to ensure a safe Return to Flight for Discovery and its crew.

Today’s announcement follows Space Shuttle Program reviews over the past two weeks. Managers identified the need to do more work to validate engineering analyses of potential debris hazards and to make some additional modifications to the external fuel tank. NASA officials and program managers agreed late Thursday to take the time to complete the work.

“This is consistent with our overall approach to the STS-114 mission, which is that we’re going to return to flight, we’re not going to rush to flight,” NASA Administrator Michael Griffin said at a morning news conference at NASA Headquarters. “Our intent with this effort is to make certain we are as safe as we know how to be before we launch the Space Shuttle and its crew. We want it to be right.”

“From the beginning we?ve been milestone-driven,” said William Readdy, NASA associate administrator for Space Operations. “This time, the milestones on debris and ice analyses, propulsion system troubleshooting and External Tank modifications drove us to retarget for July. We?ve never been reluctant to adjust the dates as information becomes available.”

The Return to Flight mission will take Shuttle Commander Eileen Collins and six crew members to the International Space Station. The mission is the first of two test flights to evaluate new thermal protection system inspection and repair techniques and to deliver supplies and equipment to the Station. A transcript of today’s news conference and follow-on technical briefing from NASA’s Johnson Space Center is available at: www.nasa.gov/returntoflight

Original Source: NASA News Release

Posted on by Fraser Cain

What’s Up This Week – May 2 – May 8, 2005

Galaxy M51. Image credit: Todd Boroson/NOAO/AURA/NSF. Click to enlarge.
Monday, May 2 – If you’re up before dawn today, look closely at the Moon – ruddy Mars will make its appearance less than 3 degrees north of its waning form.

With early evening dark skies, this would be an excellent time for mid-sized binoculars and telescope users to discover anew the fantastic “Whirlpool Galaxy”. Designated as NGC 5194, this impressive face-on spiral galaxy was discovered by Charles Messier in October of 1773 and cataloged as the M51. You can find it easily by heading about three finger-widths southwest of Eta Ursa Majoris (the end star in the handle of “the Big Dipper”) and in the same finderscope of binocular field as faint star 24 Canes Venaticorum.

At around 35 million light years away, the “Whirlpool” is a spiral delight to all optical aid. Binoculars at a dark location will see it as a large, round “haze” with a brightness toward the center. Small scopes will reveal its galactic nature and satellite galaxy, NGC 5195. With large aperture, this galaxy comes alive with detail. 10″ will clearly show spiral arm structure, while at 12.5″ knots, clusters, stellar condensations and dark dustlanes become wonderfully apparent – making the M51 one of the very few deep space objects that look like a photograph in the eyepiece. Absolutely one of the finest in the night sky!

Tuesday, May 3 – During the very early morning hours, take the opportunity that darker skies provide and view the Alpha Scorpiid meteor shower during its peak. The radiant is near Antares. Later in the morning, try using binoculars to locate Uranus as it appears a little more than three degrees north of the Moon.

Tonight’s destination is a very compact and bright little galaxy that can be seen in larger binoculars and is an easy telescope target – M94. Start by identifying past study Cor Caroli (Alpha Canum). About half a fist width to its northwest you will see Beta. Aim your scopes or binocular mid-way between the two and move slightly more than a degree towards the last star in the handle of the Big Dipper – Alkaid. The M94 was discovered in 1781 by my hero, Mechain, and this small galaxy has a powerful central core. At around 20 million light years away, smaller scopes will have difficulty resolving detail, but larger apertures under ideal conditions will pick up on its tightly-wound spiral structure.

Wednesday, May 4 – If you missed your chance to catch a “shooting star” yesterday morning, then why not try again today as the Eta Aquarids reach their peak? With a fall rate of about 21 per hour, this highly dependable annual shower is the offspring of Comet Halley. With far less Moon to interfere, these bright yellow meteors with outstanding trails are well worth looking for. If skies are cloudy, don’t worry. The Eta Aquarid stream stays active for another week.

Tonight let’s further our understanding of distance and how it effects what we see. As you know, light travels at an amazing speed of about 300,000 kilometers per second. To get a grasp on this concept, how many seconds are there in a minute? An hour? A week? A month? How about a year? Ah, you’re beginning to see the light! For every second – 300,000 kilometers. Now, go back to previous study M3 located between Arcturus and Cor Caroli. This great globular cluster is about 40,000 light years away. In terms of kilometers – that’s far more zeros than most of us can possibly understand – yet we can still see this great globular cluster.

Now let’s locate M53. Roughly halfway between Arcturus and Denebola is faint star Alpha Comae. Aim your binoculars or telescopes there and you will find the M53 about a degree northeast. This very rich, magnitude 8.7 globular cluster is almost identical to the M3, but look at what a difference an additional 25,000 light years can make to how we see it! Larger telescopes will enjoy the compact bright core as well as resolution at the cluster’s outer edges. As a bonus for scopes, look one degree to the southeast for peculiar round cluster NGC 5053. Classed as a very loose globular, this magnitude 10.5 grouping is one of the least luminous objects of its type due to low stellar population and wide separation of members – yet its distance is almost the same.

Thursday, May 5 – Today in 1961, astronaut Alan Shepard made history as he became the first American in “space”. Onboard the Mercury craft, Freedom 7, Shephard spent 15 minutes in a sub-orbital ride of a lifetime. By today’s standards this is considered “shallow space”, but your chance to view something far more distant and every bit as history making is now here.

If you did not get an opportunity to view Comet 9/P Tempel 1 last week, then try again as it will be about two degrees west/southwest of Epsilon Virginis. Projected magnitudes show that Tempel 1 should be around magnitude 10 at this time and recent observing reports indicate that it is condensing well and will be easily distinguishable as cometary. In two months time, the “Deep Impact” mission will have reached Tempel 1 and the result of its experimentation may make the comet flare brightly enough to be seen with the unaided eye. Stay tuned!

Friday, May 6 – Looking for your chance to spot Mercury? Then let the Moon be your guide as the two will appear just before dawn. The swift inner planet will appear about 3 degrees south of the slender crescent Moon for most observers.

Tonight let’s have a little bit of fun. For binocular users, we’re going to visit a large star cluster and a small galaxy. Our beginning destination is Melotte 111, a large hazy patch of stars visible to the unaided eye in Coma Berenices. Known as the “Queen’s Hair”, this five degree span of 5th to 10th magnitude stars is wonderfully rich and colorful. As legend has it, Queen Berenices offered her beautiful long tresses to the gods for the King’s safe return from battle. Touched by her love, the god’s took Berenices’ sacrifice and immortalized it in the stars.

While our next destination isn’t quite so romantic, I think you’ll enjoy getting a “Blackeye”. Located 1 degree east/northeast of 35 Comae, this small bright galaxy can be caught in the same wide binocular field northwest of previous study – M53. Originally discovered by Bode about a year before Messier cataloged it, the M64 is about 25 million light years away and holds the distinction of being one of the more massive and luminous of spiral galaxies. Telescope users will find this particular galaxy most endearing for its namesake – a very wide dark dustlane to the northeast side of the galaxy’s bright core. Power up and enjoy this very unusual treasure!

Saturday, May 7 – Tonight at at about 11:03 p.m. PDT for western United States observers in a rough line between Sacramento to Barstow and San Diego, CA (including Yuma, AZ and northern Mexico), a unique opportunity arrives to help contribute to science. A magnitude 11.7 star is being occulted by a large, and possible binary asteroid named Ophelia. According to Dr. Raoul Behrend of Geneva Observatory, “The recent lightcurve of asteroid (171) Ophelia, shows strong similarities with other binary asteroids.” While the dual nature of this asteroid is still being debated, only radar and observations during an occultation can help to help confirm it, and a single-body theory is not ruled out. “We are working on the interpretation of the lightcurve using various models:
– a single body – a pear which can reproduce the lightcurve, but with departure which seem to be significative – a single body with a huge crater (like Mathilde) – which seems to be ruled out, and
– two bodies – the most difficult to model, but preliminary results are nice. So, as we can’t exclude the single body (at 2/3 level), our preference goes actually to the binary system.” The work with Ophelia’s light curve continues further in this working document which explores sizes in the event of binarity. In a call to observers, Dr. Behrend says, “Good occultations by Ophelia are extremely rare; the last one for *many years* is around 2005-05-08 at 6h UT, over California, Arizona, and Mexico”. If Ophelia should prove to be a binary asteroid, the resulting separation would be near a maximum as predicted by Behrend’s lightcurve. “Every positive, every negative observation is important to determine the binarity state (yes or no), and the size(s). If binarity if confirmed, then the mass, scale, density, albedo and other important physical parameters could be determined with an impressive precision.”

For further information on this event, view the prediction by Steve Preston. If you are in the path of the occultation and wish further information on how to view, record and time the event, please contact Derek Breit or access this page for further instructions.

For the rest of us, we can still have lots of fun viewing another asteroid. In a matter of hours, Ceres will reach opposition and an admirable magnitude of 7. You can spot it easily tonight just northwest (and in the same binocular field) as Beta Librae. Best of luck!

Sunday, May 8 – Tonight is New Moon and time to dish you up a very special galactic treat. Located just a little less than two degrees east of 17 Comae, the NGC 4565 is one of the largest and most beautiful of edge-on galaxies. For the small telescope, it will appear as a very thin scratch of light. As aperture progresses, so does the view. With mid-sized scopes, this impressive galaxy becomes a bright, needle-like silver scratch with a small, almost stellar nucleus. For larger scopes and the trained eye, you will see perfect edge-on form with a dark dissecting dustlane. This is one extremely fine galaxy… Enjoy!

Until next week? May all your journeys be at Light Speed! ….~Tammy Plotner

Posted on by Fraser Cain

Exoplanet Image Confirmed

The brown dwarf 2M1207 and its planetary companion. Image credit: ESO/VLT/NACO. Click to enlarge.
An international team of astronomers reports today confirmation of the discovery of a giant planet, approximately five times the mass of Jupiter, that is gravitationally bound to a young brown dwarf. This puts an end to a year long discussion on the nature of this object, which started with the detection of a red object close to the brown dwarf.

In February and March of this year, the astronomers took new images of the young brown dwarf and its giant planet companion with the state-of-the-art NACO instrument on ESO’s Very Large Telescope in northern Chile. The planet is near the southern constellation of Hydra and approximately 200 light years from Earth.

“Our new images show convincingly that this really is a planet, the first planet that has ever been imaged outside of our solar system,” tells Gael Chauvin, astronomer at ESO and leader of the team of astronomers who conducted the study.

“The two objects – the giant planet and the young brown dwarf – are moving together; we have observed them for a year, and the new images essentially confirm our 2004 finding,” says Benjamin Zuckerman, UCLA professor of physics and astronomy, member of NASA’s Astrobiology Institute, and a member of the team. “I’m more than 99 percent confident.” The separation between the planet and the brown dwarf is 55 times the separation of the Earth and Sun.

Anne-Marie Lagrange, another member of the team from the Grenoble Observatory in France, looks towards the future: “Our discovery represents a first step towards one of the most important goals of modern astrophysics: to characterize the physical structure and chemical composition of giant and, eventually, terrestrial-like planets.”

Last September, the same team of astronomers reported a faint reddish speck of light in the close vicinity of a young brown dwarf (see ESO PR 23/04). The feeble object, now called 2M1207b, is more than 100 times fainter than the brown dwarf, 2M1207A. The spectrum of 2M1207b presents a strong signature of water molecules, thereby confirming that it must be cold. Based on the infrared colours and the spectral data, evolutionary model calculations led to the conclusion that 2M1207b is a 5 Jupiter-mass planet. Its mass can be estimated also by use of a different method of analysis, which focuses on the strength of its gravitational field; this technique suggests that the mass might be even less than 5 Jupiters.

At the time of its discovery in April 2004, it was impossible to prove that the faint source is not a background object (such as an unusual galaxy or a peculiar cool star with abnormal infrared colours), even though this appeared very unlikely. Observations with the Hubble Space Telescope, obtained in August 2004, corroborated the VLT/NACO observations, but were taken too soon after the NACO ones to conclusively demonstrate that the faint source is a planet.

The new observations show with high confidence that the two objects are moving together and hence are gravitationally bound.

“Given the rather unusual properties of the 2M1207 system, the giant planet most probably did not form like the planets in our solar system,” says Gael Chauvin. “Instead it must have formed the same way our Sun formed, by a one-step gravitational collapse of a cloud of gas and dust.”

The paper describing this research has been accepted for publication in Astronomy and Astrophysics.

The same European/American team has had another paper just accepted for publication in Astronomy & Astrophysics; this paper reports the imaging discovery with the same VLT/NACO instrumentation of a lightweight companion to AB Pictoris, a young star located about 150 light years from Earth. The estimated mass of the companion is between 13 and 14 times the mass of Jupiter, which places the companion right on the border line between massive planets and the lowest mass brown dwarfs.

Original Source: ESO News Release

Posted on by Fraser Cain

Time to Concentrate on Saturn’s Rings

Cassini view of Saturn’s rings. Image credit: NASA/JPL/SSI. Click to enlarge.
The Cassini spacecraft is about to embark on a new mission phase that will give it a ringside seat at Saturn — literally. After concentrating on flybys of the stately planet’s moons since arriving last year, Cassini will begin five months of extensive study of Saturn’s magnificent rings. Knowing how the rings form and how long they have been there is a central question for the Cassini mission.

Cassini will view the rings on their lit and unlit faces, both toward the Sun and away from the Sun. This range of geometries will allow all of Cassini’s various instruments to observe the rings as never before.

This grand mosaic consists of 126 images acquired in a tile-like fashion, covering one end of Saturn’s rings to the other and the entire planet in between.

Saturn’s Crown Jewels
From a distance, the majestic rings of Saturn look like symmetrical hoops surrounding the planet. Up close, however, the rings turn out to be a splendid but somewhat unruly population of ice and rock particles jostling against each other or being pushed and pulled into uneven orbits by bigger particles and by Saturn’s many moons.

Their origin is a mystery. Scientists think the rings did not form out of the initial cloud of gas and dust that surrounded Saturn as it formed, but are actually much younger than the planet. However, they do not know if the rings formed after an incoming comet was torn apart by Saturn’s gravity, or if some previous moon of Saturn was smashed to bits by an incoming comet.

Although the rings stretch over 282,000 kilometers (175,000 miles) — about three-fourths of the distance from Earth to the moon — they may be as little as 30 meters (roughly 100 feet) in thickness. The mass of all the ring particles measured together would comprise a moon about the size of Mimas, one of Saturn’s medium-small moons. The rings may in fact be at least partly composed of the remnants of such a moon or moons, torn apart by gravitational forces.

Named in order of discovery, the labels scientists have assigned to the major rings do not indicate their relative positions. From the planet outward, they are known as the D, C, B, A, F, G and E rings.

The images that make up this composition were obtained from Cassini’s vantage point beneath the ring plane with the narrow angle camera on June 21, 2004, at a distance of 6.4 million kilometers (4 million miles) from Saturn.

Running Rings Around Saturn
Cassini’s tour of Saturn has been planned to include three ring observation periods. Much of Cassini’s flight path so far has been along the plane of the rings, where basically the spacecraft sees the rings edge-on.

The first sequence of ring observations, about to begin, runs through early September and will take Cassini seven times around Saturn and its rings. These orbits will be inclined from the ring plane by 24 degrees. The second set of ring orbits occurs between summer 2006 and summer 2007, when the inclination gets up to 53 degrees. Late in the Cassini tour, starting in the fall of 2007, the third set of inclined orbits begins, and by the end of the mission in summer 2008, the inclination of the orbit reaches nearly 80 degrees. This will mean viewing the rings from almost straight above.

Naturally, many new images will be taken, including the first complete global studies of several interesting regions in the rings, including the kinky F ring. Some other first-time events are: high-resolution, full-color images of the rings; radio wavelength mapping of the rings, using Cassini’s main antenna; in-depth studies of thermal emission from the rings over a range of geometries; complete, high-resolution radial scans of the rings in near-infrared, which will provide information on composition of the rings. There will also be a number of new “occultations” of stars by the rings, when stars pass behind the rings from Cassini’s point of view; these will be studied by two different instruments. Also in store are the first occultations by the rings of Cassini’s radio signal, meaning that the signal will pass through the rings en route from the spacecraft to Earth. These will be studied at three radio wavelengths.

During these occultations, scientists will watch how a beam of light from a star or the radio waves from Cassini’s transmitter are affected by the ring material as they pass through the ring. Each occultation experiment provides an opportunity for an extremely high-resolution study of a single path across the rings with resolutions of about 100 meters (330 feet) – some even have resolution as fine as 10 to 20 meters (33 to 66 feet). NASA’s two Voyager spacecraft conducted one radio occultation and one stellar occultation by the rings. During its lifetime, Cassini will obtain 14 radio occultations and 80 stellar occultations, giving far more detailed studies of the ring structures.

The radio experiments will use Cassini’s radio antennas and the ground-based antennas of NASA’s Deep Space Network. From these measurements, scientists can derive information about the structures, composition, densities and sizes of ring particles. New moons may also be discovered from their effects on the ring material.

Original Source: NASA/JPL News Release

Posted on by Fraser Cain

Near Perfect “Einstein Ring” Discovered

Near perfect “Einstein Ring” gravitational lens. Image credit: ESO/VLT. Click to enlarge.
This is Einstein’s Year. One-hundred years ago a little known Swiss patent clerk in the very early years of a scientific career was confronted with a series of paradoxes related to time and space, energy and matter. Gifted with a profound intuition and a powerful imagination, Albert A. Einstein rose out of obscurity to present an entirely new way of looking at natural phenomenon. Einstein showed us all that time had very little to do with clocks, energy has less to do with quantity and more to do with quality, space was not just ?a big square box to put stuff in”, matter and energy were two sides of the same cosmic coin, and gravity had a profound effect on everything – light, matter, time, and space.

Today we use all these principles ? enunciated a century ago – to probe the most distant things in the Universe. Because of Einstein’s investigation of the photoelectric effect, we now understand why light is not continuous but curiously riddled with dark and bright lines telling us when that light was emitted, what emitted it. and the kinds of things touching it in its travels. Because of Einstein’s insight into the conversion of mass and energy, we now understand how distant suns illuminate the cosmos, and how powerful magnetic fields whip particles up to stupendous speeds later to come crashing down on the Earth’s atmosphere. And because gravity is now understood to influence everything, we have learned how distant objects can capture and focus light from even more distant objects.

Although we have yet to find an absolutely perfect instance of gravitational lensing in the Universe, today we are much closer to that ideal. In a paper entitled “Discovery of a high red-shift Einstein Ring” published April 27, 2005, Remi Cabanac of Canada-France-Hawaii Telescope, in Hawaii and associates “report the discovery of a partial Einstein ring … produced by a massive (and seemingly isolated) elliptical galaxy.” Previous to this find, the most complete Einstein ring discovered was documented in 1996 by S.J. Warren of the Imperial College in London. That ring – also one of the few visible in optical light – is slightly less than a half-circle in circumference (170 degrees).

Remi Cabanac explained that he “discovered the system while observing at the European Southern Observatory Very Large Telescope in Chile with a spectro imager called FORS1.” Remi says he was fullfilling his responsibilties as a service astronomer, “observing for Helmut Jerjen (co-author of the paper) doing deep imaging of nearby dwarf galaxies in the outskirts of a well-known nearby galaxy cluster in Fornax.” Remi continued to say that his “eye got attracted by the very unusual bright arc in the northwest of the field, I knew it was something pretty amazing because lensing arcs are usually very dim, and I was observing in red band whereas arcs are usually blueish.”

To confirm his suspicions of a new discovery Remi “went to the astronomical database but nothing existed under the coordinates.” Later Remi consulted with “Chris Lidman (another co-author and lens expert) and showed him the image. He couldn’t believe it was a lens at first because it was so bright and conspicuous, Chris thought it could be an artefact on the image.” With Chris’ support, Remi “applied for spectroscopic follow-up and realized that it was both a true gravitational lense and a very significant discovery, because the background source was highly amplified and very far away.”

According to the paper, the ring inscribes a “C-shaped” circle of 270 degrees in near-complete circumference with an apparent radius of slightly more than 1 3/4 arc seconds – roughly the size of a star’s “virtual” image seen at high power through a small amateur telescope. The lens galaxy is a giant elliptical similar to M87 in the Virgo-Coma cluster. The lens lies some 7 billion light years distant in the direction of the constellation Fornax (visible from warmer temperate northern hemisphere and southern hemisphere skies). The source galaxy bears a red shift of 3.77 – suggesting a recessionary distance of roughly 11 BLYs. Source and lens galaxy have received the designation FOR J0332-3557 3h32m59s, -35d57m51s and lie proximate to the Fornax galaxy cluster – but well beyond it in terms of real space.

What makes this particular discovery so interesting astronomically is the fact that the lens galaxy is very massive, is in a period of star-birth quiescence, lies at such a great distance from the Earth, and may be isolated from other cluster galaxies in its own spatial locale. Meanwhile the source galaxy is significantly brighter (by one absolute stellar magnitude) than other Lyman break galaxies (galaxies that red-shift the Lyman Break at 912 angstroms into the visible part of the spectrum), is poor in emission line spectra, and recently had completed a cycle of rapid star birth (“starburst”). All these factors combined mean that FOR J0332 could provide a wealth of data concerning galaxy formation before the current inflationary epoch of the Universe.

According to the science team, “One of the key issues in galaxy formation within the current LCDM (Lambda Cold Dark Matter) framework of structure formation is the mass assembly histories of galactic halos.” Current thinking is that galaxies accumulate halo mass – that huge spherical bulge of low luminosity matter surrounding galactic cores – before star formation really kicks in. One way to investigate this idea is to determine how mass-to-light ratios change over time as galaxies evolve. But to do that you need to sample the masses and luminosities of as many galaxies as possible, of a variety of types, over the broadest possible range of space and time.

The discovery of FOR J0332 – and the three other partial Einstein ring objects – helps astronomers by adding examples of galaxies normally undetectable at great distances. From the paper, “Various deep surveys have uncovered different galaxy populations, but the selection criteria produced biased samples: UV-selected and narrow-band selected samples are sensitive to actively star-forming galaxies and biased against quiescent, evolved systems while sub-millimeter and near-infrared surveys select dusty starburst galaxies and very red galaxies respectively.”

What conclusions can we draw based on this discovery?

Remi underscores the significance of this find by saying “The source amplified by the lens is the galaxy with the brightest apparent luminosity ever discovered at such a distance. It will give us unique information on the physical conditions prevailing in the interstellar medium when the universe was only 12% of its present age. The shape of the source is also very important because it gives the amount of mass within the lens at a redshift of z=1. Only a handful of Einstein rings have been discovered at such high redshift. It will give an important measurement at how elliptical galaxy mass evolved through time.”

Written by Jeff Barbour

Posted on by Fraser Cain

Robots Will Search for Lunar Water Deposits

NASA is gearing up to send humans back to the Moon. Image credit: Pat Rawlings / SAIC. Click to enlarge.
The next time you look at the Moon, pause for a moment and let this thought sink in: People have actually walked on the Moon, and right now the wheels are in motion to send people there again.

The goals this time around are more ambitious than they were in the days of the Apollo program. NASA’s new Vision for Space Exploration spells out a long-term strategy of returning to the Moon as a step toward Mars and beyond. The Moon, so nearby and accessible, is a great place to try out new technologies critical to living on alien worlds before venturing across the solar system.

Whether a moonbase will turn out to be feasible hinges largely on the question of water. Colonists need water to drink. They need water to grow plants. They can also break water apart to make air (oxygen) and rocket fuel (oxygen+hydrogen). Furthermore, water is surprisingly effective at blocking space radiation. Surrounding the ‘base with a few feet of water would help protect explorers from solar flares and cosmic rays.

The problem is, water is dense and heavy. Carrying large amounts of it from Earth to the Moon would be expensive. Settling the Moon would be so much easier if water were already there.

It’s possible: Astronomers believe that comets and asteroids hitting the Moon eons ago left some water behind. (Earth may have received its water in the same way.) Water on the Moon doesn’t last long. It evaporates in sunlight and drifts off into space. Only in the shadows of deep cold craters could you expect to find any, frozen and hidden. And indeed there may be deposits of ice in such places. In the 1990s two spacecraft, Lunar Prospector and Clementine, found tantalizing signs of ice in shadowed craters near the Moon’s poles–perhaps as much as much as a cubic kilometer. The data were not conclusive, though.

To find out if lunar ice is truly there, NASA plans to send a robotic scout. The Lunar Reconnaissance Orbiter, or “LRO” for short, is scheduled to launch in 2008 and to orbit the Moon for a year or more. Carrying six different scientific instruments, LRO will map the lunar environment in greater detail than ever before.

“This is the first in a string of missions,” says Gordon Chin, project scientist for LRO at NASA’s Goddard Space Flight Center. “More robots will follow, about one per year, leading up to manned flight” no later than 2020.

LRO’s instruments will do many things: they’ll map and photograph the Moon in detail, sample its radiation environment and, not least, hunt for water.

For example, the spacecraft’s Lyman-Alpha Mapping Project (LAMP), will attempt to peer into the darkness of permanently shadowed craters at the Moon’s poles, looking for signs of ice hiding there.

How can LAMP see in the dark? By looking for the dim glow of reflected starlight.

LAMP senses a special range of ultraviolet light wavelengths. Not only is starlight relatively bright in this range, but also the hydrogen gas that permeates the universe radiates in this range as well. To LAMP’s sensor, space itself is literally aglow in all directions. This ambient lighting may be enough to see what lies in the inky blackness of these craters.

“What’s more, water ice has a characteristic spectral ‘fingerprint’ in this same range of ultraviolet light, so we’ll get spectral evidence of whether ice is in these craters,” explains Alan Stern, a scientist at the Southwest Research Institute and principal investigator for LAMP.

The spacecraft is also equipped with a laser that can shine pulses of light into dark craters. The main purpose of the instrument, called the Lunar Orbiter Laser Altimeter (LOLA), is to produce a highly accurate contour map of the entire Moon. As a bonus, it will also measure the brightness of each laser reflection. If the soil contains ice crystals, as little as 4%, the returning pulse would be noticeably brighter.

LOLA by itself can’t prove that ice is there. “Any kind of reflective crystals could produce brighter pulses,” explains David Smith, principal investigator for LOLA at NASA’s Goddard Space Flight Center. “But if we see brighter pulses only in these permanent shadows, we’d strongly suspect ice.”

One of LRO’s instruments, named Diviner, will map the temperature of the Moon’s surface. Scientists can use these measurements to search for places where ice could exist. Even in the permanent shadows of polar craters, temperatures must be very low for ice to resist evaporation. Thus, Diviner will provide a “reality check” for LRO’s other ice-sensitive instruments, identifying areas where positive signs of ice would not make any sense because the temperature is simply too high.

Another reality check will come from LRO’s Lunar Exploration Neutron Detector (LEND), which counts neutrons spraying out of the lunar surface. Why does the Moon emit neutrons? And what does that have to do with water? The Moon is constantly bombarded by cosmic rays, which produce neutrons when they hit the ground. Hydrogen-bearing compounds like H2O absorb neutrons, so a dip in neutron radiation could signal an oasis … of sorts. LEND is being developed by Igor Mitrofanov from the Institute for Space Research, Federal Space Agency, Moscow.

“There’s a strong synergy between the various instruments on LRO,” notes Chin. “None of these instruments alone could provide definitive evidence of ice on the Moon, but if they all point to ice in the same area, that would be compelling.”

Chin also points out another reason that finding ice near the Moon’s poles would be exciting:

Not far from some permanently shadowed craters are mountainous regions in permanent sunlight, known romantically as “peaks of eternal sunshine.” Conceivably, a moonbase could be placed on one of those peaks, providing astronauts with constant solar power–not far from crater-valleys below, rich in ice and ready to be mined.

Wishful thinking? Or a reasonable plan? Lunar Reconnaissance Orbiter will beam back the answer.

Original Source: Science@NASA Story

Posted on by Fraser Cain

Mars Express Radar Boom to Be Deployed in May

MARSIS on board ESA’s Mars Express will employ ground-penetrating radar to map underground water. Image credit: ESA. Click to enlarge.
Following green light for the deployment of ESA?s Mars Express radar, given in February this year, the radar booms are now planned to be deployed in the first half of May.

Once the deployment is successful, the Mars Express MARSIS radar will enable the first European spacecraft to orbit Mars to complement its study of the planet?s atmosphere and surface.

MARSIS (Mars Advanced Radar for Subsurface and Ionosphere Sounding instrument) is the first antenna of its kind which was also designed to actually look below the surface of Mars at the different layers of material, most notably for water.

The deployment of the three MARSIS radar booms is an operation which will take place in three phases, in a window spanning from 2 to 12 May 2005. These operations will be initiated and monitored from ESA?s European Space Operations Centre (ESOC) in Darmstadt, Germany.

Each boom will be deployed separately, with the two 20-metre ?dipole? booms to be unfurled first and the 7-metre ?monopole? boom to follow a few days later.

Before each deployment, the spacecraft will be placed in a ?robust? attitude control mode, which will allow it to tumble freely while the boom extends before regaining standard pointing to the Sun and Earth.

After each deployment, the control team will conduct a full assessment of the spacecraft status before a decision is taken to proceed with the next phase.

The result of each deployment can be assessed only after a series of tests, each taking few days. After the deployment of the three booms, ESA engineers will start the analysis of the complete behaviour of the satellite to be able to confirm the overall success of the operation.

The current schedule is subject to changes, because the timing of the complex series of operations cannot be all fixed beforehand. A status report will follow in due course.

Once the deployment is complete, MARSIS will undergo three weeks of commissioning before the start of actual science investigations, ready for when one of the prime regions of interest for radar observations comes into the right position through the natural evolution of the spacecraft?s orbit.

The MARSIS instrument was developed by the University of Rome, Italy, in partnership with NASA?s Jet Propulsion Laboratory (JPL) in Pasadena, California, USA.

Original Source: ESA News Release

Posted on by Fraser Cain

Tithonium Chasma on Mars

Tithonium Chasma, a major trough at the western end of the Valles Marineris canyon on Mars. Image credit: ESA. Click to enlarge.
This image, taken by the High Resolution Stereo Camera (HRSC) on board ESA?s Mars Express spacecraft, shows part of Tithonium Chasma, a major trough at the western end of the Valles Marineris canyon on Mars.

The image was taken during orbit 887 with a ground resolution of approximately 13 metres per pixel.

The displayed region is located at the beginning of the canyon system at about latitude 5? South and longitude 280? East. North is to the right of the image.

Tithonium Chasma extends roughly from east to west and runs parallel to Ius Chasma. It ranges from approximately 10 to 110 kilometres wide, narrows in an easterly (top to bottom) direction and has a maximum depth of about 3.5 to 4 kilometres.

The colour image covers the eastern part of Tithonium Chasma. Along the slopes of the trough (centre), linear features due to erosion are visible. At the base of the northern wall (on the right of the black and white image), an apron of material has a longitudinal ridge pattern and may have been caused by a large landslide (see close-up, right).

Dune fields are scattered throughout the trough, including the north-east portion of a crater. A string of depressions on the plains in the south-west of the image may be caused by surface collapse. These features are common to this region and extend parallel to Valles Marineris.

Nearby, prominent linear features are visible and may be faults associated with the formation of the Tharsis Rise, located to the west of Valles Marineris and extending to a height of 8 to 10 kilometres. Some of these faults can be seen faintly extending into the trough.

In the eastern part of the trough, an interesting hill exhibits linear features. These structures are highlighted in the following close-up and perspective views and could have been caused by fluvial or ‘aeolian’ (wind-related) erosion. The darker material to the south of this hill is thought to be underlying material that has been exposed by wind erosion.

By cutting deep into the Martian surface, this area of Valles Marineris provides a window into geological and climatic history of the planet. Valles Marineris has had a complex evolution and has been shaped by tectonic, volcanic and glacial processes, as well as possibly fluvial or aeolian erosion.

Data from the HRSC, coupled with information from the other instruments on ESA?s Mars Express and other missions, will provide new insights into the geological evolution of the Red Planet and also pave the way for future missions.

Original Source: ESA News Release

Posted on by Fraser Cain

Deep Impact Has Its Target in View

Deep Impact’s first view of Comet Temple 1 from a distance of 64 million kilometers (39.7 million miles). Image credit: NASA/JPL. Click to enlarge.
Sixty-nine days before it gets up-close-and-personal with a comet, NASA’s Deep Impact spacecraft successfully photographed its quarry, comet Tempel 1, from a distance of 64 million kilometers (39.7 million miles).

The image, the first of many comet portraits it will take over the next 10 weeks, will aid Deep Impact’s navigators, engineers and scientists as they plot their final trajectory toward an Independence Day encounter. “It is great to get a first glimpse at the comet from our spacecraft,” said Deep Impact Principal Investigator Dr. Michael A’Hearn of the University of Maryland, College Park, Md. “With daily observations beginning in May, Tempel 1 will become noticeably more impressive as we continue to close the gap between spacecraft and comet. What is now little more than a few pixels across will evolve by July 4 into the best, most detailed images of a comet ever taken.”

The ball of dirty ice and rock was detected on April 25 by Deep Impact’s medium resolution instrument on the very first attempt. While making the detection, the spacecraft’s camera saw stars as dim as 11th visual magnitude, more than 100 times dimmer than a human can see on a clear night.

“This is the first of literally thousands of images we will take of Tempel 1 for both science and navigational purposes,” said Deputy Program Manager Keyur Patel at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “Our goal is to impact a one-meter long (39-inch) spacecraft into about a 6.5-kilometer wide (4-mile) comet that is bearing down on it at 10.2 kilometers per second (6.3 miles per second), while both are 133.6 million kilometers (83 million miles) away from Earth. By finding the comet as early and as far away as we did is a definite aid to our navigation.”

To view the comet image on the Internet, visit http://www.nasa.gov/deepimpact or http://deepimpact.jpl.nasa.gov/.

Deep Impact is comprised of two parts, a “flyby” spacecraft and a smaller “impactor.” The impactor will be released into the comet’s path for a planned high-speed collision on July 4. The crater produced by the impact could range in size from the width of a large house up to the size of a football stadium and from 2 to 14 stories deep. Ice and dust debris will be ejected from the crater, revealing the material beneath.

The Deep Impact spacecraft has four data collectors to observe the effects of the collision – a camera and infrared spectrometer comprise the high resolution instrument, a medium resolution instrument, and a duplicate of that camera on the impactor (called the impactor targeting sensor) that will record the vehicle’s final moments before it is run over by comet Tempel 1 at a speed of about 37,000 kilometers per hour (23,000 miles per hour).

The overall Deep Impact mission management for this Discovery class program is conducted by the University of Maryland. Deep Impact project management is handled by the Jet Propulsion Laboratory. The spacecraft was built for NASA by Ball Aerospace & Technologies Corporation, Boulder, Colo.

For more information about Deep Impact on the Internet, visit NASA Deep Impact.

Original Source: NASA/JPL News Release