Posted on by Fraser Cain

Mars and Back in 90 Days on a Mag-Beam

A new means of propelling spacecraft being developed at the University of Washington could dramatically cut the time needed for astronauts to travel to and from Mars and could make humans a permanent fixture in space.

In fact, with magnetized-beam plasma propulsion, or mag-beam, quick trips to distant parts of the solar system could become routine, said Robert Winglee, a UW Earth and space sciences professor who is leading the project.

Currently, using conventional technology and adjusting for the orbits of both the Earth and Mars around the sun, it would take astronauts about 2.5 years to travel to Mars, conduct their scientific mission and return.

“We’re trying to get to Mars and back in 90 days,” Winglee said. “Our philosophy is that, if it’s going to take two-and-a-half years, the chances of a successful mission are pretty low.”

Mag-beam is one of 12 proposals that this month began receiving support from the National Aeronautics and Space Administration’s Institute for Advanced Concepts. Each gets $75,000 for a six-month study to validate the concept and identify challenges in developing it. Projects that make it through that phase are eligible for as much as $400,000 more over two years.

Under the mag-beam concept, a space-based station would generate a stream of magnetized ions that would interact with a magnetic sail on a spacecraft and propel it through the solar system at high speeds that increase with the size of the plasma beam. Winglee estimates that a control nozzle 32 meters wide would generate a plasma beam capable of propelling a spacecraft at 11.7 kilometers per second. That translates to more than 26,000 miles an hour or more than 625,000 miles a day.

Mars is an average of 48 million miles from Earth, though the distance can vary greatly depending on where the two planets are in their orbits around the sun. At that distance, a spacecraft traveling 625,000 miles a day would take more than 76 days to get to the red planet. But Winglee is working on ways to devise even greater speeds so the round trip could be accomplished in three months.

But to make such high speeds practical, another plasma unit must be stationed on a platform at the other end of the trip to apply brakes to the spacecraft.

“Rather than a spacecraft having to carry these big powerful propulsion units, you can have much smaller payloads,” he said.

Winglee envisions units being placed around the solar system by missions already planned by NASA. One could be used as an integral part of a research mission to Jupiter, for instance, and then left in orbit there when the mission is completed. Units placed farther out in the solar system would use nuclear power to create the ionized plasma; those closer to the sun would be able to use electricity generated by solar panels.

The mag-beam concept grew out of an earlier effort Winglee led to develop a system called mini-magnetospheric plasma propulsion. In that system, a plasma bubble would be created around a spacecraft and sail on the solar wind. The mag-beam concept removes reliance on the solar wind, replacing it with a plasma beam that can be controlled for strength and direction.

A mag-beam test mission could be possible within five years if financial support remains consistent, he said. The project will be among the topics during the sixth annual NASA Advanced Concepts Institute meeting Tuesday and Wednesday at the Grand Hyatt Hotel in Seattle. The meeting is free and open to the public.

Winglee acknowledges that it would take an initial investment of billions of dollars to place stations around the solar system. But once they are in place, their power sources should allow them to generate plasma indefinitely. The system ultimately would reduce spacecraft costs, since individual craft would no longer have to carry their own propulsion systems. They would get up to speed quickly with a strong push from a plasma station, then coast at high speed until they reach their destination, where they would be slowed by another plasma station.

“This would facilitate a permanent human presence in space,” Winglee said. “That’s what we are trying to get to.”

Original Source: University of Washington News Release

Posted on by Fraser Cain

Preparing for Huygens’ Release

Image credit: NASA/JPL/SSI
On Jan. 14, 2005, the Huygens probe will plow into the orange atmosphere of Saturn’s moon, Titan, becoming the first spacecraft to attempt to land on a moon in our solar system since the Soviet Union’s Luna 24 touched down on Earth’s moon in 1976.

Though scientists hope that Huygens will survive the plunge, it will be flying blind through hydrocarbon haze and methane clouds to a surface that could consist of seven-kilometer-high ice mountains and liquid methane seas.

That’s the picture that emerges from a series of articles – half of them by University of California, Berkeley, researchers – published in the journal Geophysical Research Letters last month and detailing what scientists know to date about the surface, atmosphere and magnetic field of Titan. This view sets the stage for an analysis of new data soon to arrive from the Cassini spacecraft and Huygens probe.

“These (journal) papers really give a state-of-the-art picture of Titan, before Cassini goes into orbit around Saturn and the Huygens probe goes into Titan’s atmosphere,” said Imke de Pater, a professor of astronomy at UC Berkeley who wrote the introductory paper in the series and co-authored four of the nine papers. The papers came out of a meeting De Pater hosted last November at UC Berkeley to discuss what has been gleaned to date about the moon from optical, infrared and radar telescopes, including the Hubble Space Telescope and the twin Keck Telescopes in Hawaii.

Scientists expect the current sketchy picture of Titan’s surface, totally obscured by clouds and haze, will much improve when the Cassini spacecraft, which is carrying the Huygens probe, starts an intense observation of Titan later this month. While on-board infrared imaging cameras can pierce the cloud cover, however, they can only reveal bright and dark spots on the surface, which are difficult to interpret. What Huygens will encounter at Titan’s surface will remain a mystery until the probe plops into an ocean or parachutes to solid ground.

“Based upon their spectral characteristics, the bright areas imaged by various Earth-bound telescopes and the Hubble Space Telescope could be a mixture of rock and water ice,” de Pater said. Such a mixture appears relatively bright in comparison with substances like tar and liquid hydrocarbons, which absorb essentially all sunlight at these wavelengths and hence appear very dark.

“The dark areas could contain liquid hydrocarbons,” she said. “But they’re all still a mystery.”

Some scientists have suggested that one large bright area, Xanadu, is a mountain of rock and water ice that stands out because runoff (hydrocarbon rain) has washed off the dark hydrocarbon particles. UC Berkeley graduate student J. Taylor Perron and de Pater concluded in one of the papers that such an ice continent, primarily composed of water ice, could be no higher than 3 to 7 kilometers – that is, at most, 23,000 feet, about the height of Mt. Aconcagua in Argentina. That is even more impressive on a globe less than half the diameter of Earth.

The Huygens probe, which will take from two to two and a half hours to float to the surface, is aiming for a landing site in a dark area bordering a bright area near the equator, so it could land instead in a gasoline-like hydrocarbon brew of methane, propane or butane. Though the probe is designed to float, its builders expect, at most, 45 minutes of data once it sets down. A few minutes would be cause for celebration.

The Cassini/Huygens spacecraft was launched from Kennedy Space Center in 1997, the product of an international collaboration between three space agencies – the National Aeronautics and Space Administration, the European Space Agency and the Italian Space agency – involving contributions from 17 nations. It arrived at Saturn in July 2004, beginning a four-year mission to photograph and collect data on Saturn, its rings and moons. This Oct. 26, it will get within 1,000 kilometers of Titan – closer than ever before – turning its remote sensing instruments on that moon’s surface and atmosphere. Cassini will release the Huygens probe on Christmas Day, Dec. 25.

The second largest moon in the solar system and the only one with a thick, methane-rich, nitrogen atmosphere, Titan intrigues scientists because of its resemblance to a young Earth. The atmospheres of both Titan and the early Earth were dominated by nearly the same amount of nitrogen, and the chemistry discovered on Titan could provide clues to the origins of life on our planet.

De Pater and chemistry graduate student Mate Adamkovics have used the adaptive optics on the Keck Telescope in Hawaii to image the hydrocarbon haze that envelops the moon, taking snapshots at various altitudes from 150 to 200 kilometers down to the surface. In the movie they constructed from these snapshots, haze is very evident in the atmosphere at about 30-50 kilometers over the South Pole. Stratospheric haze at about 150 kilometers is visible over a large area in the northern hemisphere but not the southern hemisphere, an asymmetry observed previously. And at the southern hemisphere’s tropopause – the border between the lower atmosphere and the stratosphere at about 42 kilometers altitude – cirrus haze is visible, analogous to cirrus haze on Earth.

These observations agree with a theory of haze formation whereby sunlight creates haze particles at a high altitude – 400 to 600 kilometers above the surface – that are blown to the winter pole, where the haze accumulates as a polar “hood.” The haze particles start to settle out and are carried by a lower-elevation return flow to the summer hemisphere.

Laboratory experiments by Melissa Trainer of the University of Colorado, Boulder, reported in the journal suggest that the haze particles could be polycyclic aromatic hydrocarbons if the methane concentration in the atmosphere is high – around 10 percent – though they would be primarily long-chain hydrocarbons at low concentrations. The Huygens probe will measure gas concentrations as it plummets through the atmosphere, hopefully testing this connection between methane concentration and aerosol composition.

Cassini’s observations of Titan over the next four years should yield much more information about the atmospheric haze and surface topography, as well as raise new questions. De Pater urges ground-based astronomers to continue to observe Titan’s moon, “so the Cassini/Huygens data can be tied in with the long-term data base on Titan’s seasons,” she wrote.

De Pater herself will be peering at Titan through the Keck Telescope on Jan. 15 when the Huygens probe disappears into the atmosphere.

“I’m skeptical that we’ll see a meteor trail, as some have predicted, but our observations will give us a good image of Titan at the time of probe entry, which could be very relevant to calibrating Titan at entry time,” de Pater said.

De Pater’s research is supported by the National Science Foundation. The Nov. 17, 2003, workshop on Titan was sponsored by the Center for Integrative Planetary Studies at UC Berkeley.

Original Source: Berkeley News Release

Posted on by Fraser Cain

New Insights Into Saturn’s Magnetosphere

University of California scientists working at Los Alamos National Laboratory have begun to analyze data from an instrument aboard the joint U.S.-European spacecraft Cassini. Although Cassini has only been orbiting the planet Saturn since July 1, data from the Cassini Plasma Spectrometer (CAPS) has already begun to provide new information about the curious nature of Saturn’s space environment.

CAPS had been detecting advance readings for several days before Cassini finally crossed the bow shock that exists in the solar wind ahead of the magnetosphere, a huge magnetic field bubble produced in the solar wind by Saturn’s strong magnetic field. On June 28, the spacecraft entered into the magnetosphere itself and began taking data. From this very preliminary set of measurements, it is apparent that the outer reaches of Saturn’s magnetosphere are probably populated by plasma captured from the solar wind, but closer to the planet the plasma comes primarily from the rings and/or the inner icy satellites.

According to Michelle Thomsen, the current Los Alamos CAPS project leader, “After many years of design, development and testing, and then the seven-year journey across the solar system, CAPS is finally doing the job it was built to do. We are quickly learning much, but I think we have only begun to understand what CAPS can teach us about Saturn and its space environment over the next few years.”

CAPS consists of three separate analyzers designed to measure the electrically charged particles trapped within Saturn’s magnetosphere. Los Alamos played a major role in the design and construction of two of them: an ion mass spectrometer (IMS), which incorporates a novel design developed at Los Alamos to identify the different atomic species in Saturn’s magnetospheric plasma, and an ion beam spectrometer (IBS), which is based on a design used by Los Alamos scientists on several previous solar wind research missions.

During Cassini’s first brief pass over Saturn’s rings, CAPS identified a previously unknown low-energy plasma trapped on the magnetic field lines threading the Cassini Division, the name given to the gap between the main A and B rings. With the four-year mission just beginning, including more than 70 orbits of the planet, CAPS is poised to provide scientists with a new level of understanding about Saturn’s space environment, as well as clues about some of the space physics processes that operate more universally in the solar system.

The CAPS team involves scientists and engineers from 14 institutions and six countries, including Dave Young, the Principal CAPS Investigator at the Southwest Research Institute in San Antonio, Texas. At Los Alamos, the CAPS effort was made possible by the work of numerous members of International, Space and Response Division and its predecessor organizations. The IMS was designed by Los Alamos staff member Beth Nordholt and former staff member Dave McComas. In addition to Thomsen, current members of the team include Bruce Barraclough (lead investigator for the IBS), Dot Delapp, Jack Gosling, Dan Reisenfeld, John Steinberg, Bob Tokar and summer student Brian Fish.

Los Alamos National Laboratory is operated by the University of California for the National Nuclear Security Administration (NNSA) of the U.S. Department of Energy and works in partnership with NNSA’s Sandia and Lawrence Livermore national laboratories to support NNSA in its mission.

Los Alamos enhances global security by ensuring the safety and reliability of the U.S. nuclear deterrent, developing technologies to reduce threats from weapons of mass destruction, and solving problems related to defense, energy, environment, infrastructure, health and national security concerns.

Original Source: Los Alamos News Release

Posted on by Mark Mortimer

Book Review: Futures – 50 Years in Space, The Challenge of the Stars

Much like an art gallery, this book is all about its illustrations. Most of these fall under the same spell. There is a foreground view of a planet’s surface (or other such body floating in space). Sometimes the landscape is littered with human artifacts or other alien artifacts. However often it is devoid of life altogether, much like a graveyard. ‘Above’ the surface, orientation of course being very relative, swirls a supernatural ether. ‘Day’ time views (again time being relative) have ghostly perspectives of familiar or quite unusual planets and asteroids whispering into or out of the ether. Night views are clear, without an obfuscating atmosphere, but don’t expect to see recognizable constellations. For example with Alpha Centauri in near proximity, patterns of other stars are quite original. Though the authors use this same spell to weave their magic many times over, each resulting visage is compelling and intriguing in its own right.

And with the universe as the subject matter there is no lack of material. In a similar manner to most astronomy books, this one starts with views of the Earth’s moon and then it soars out. Mars has extensive coverage. Following this are the remaining planets of the solar system and/or their asteroids. Most astronomy books don’t include pictures of surfaces hereafter as even Pluto hasn’t had any significant imaging done of its surface. But here is perhaps where Hardy and Moore excel. Rather than restricting themselves to well known visages, they push a reader into the unknown. There is an Algol-type binary where a small blue white star can be seen scavenging material from its neighbour orange giant. Or, one can see a city which is lit up at night by the glow resulting from a nearby globular cluster. Perhaps no images like these exist anywhere, but perhaps they do, and this speculation adds to the impact of each artwork. Maybe in hundreds of years such an image will be viewed by people or by a robotic probe. Until then we will have to rely on the skills of imaginative seers like Hardy and Moore to bring us such pleasurable treats.

The title itself is a bit misleading, but no deception is intended. The theme of this book is to provide images of what might be seen by future travels, hence futures is in the title. Hardy and Moore first conceived the idea of making an illustrated book of space art in 1954. Hence 50 years is in the title. They did complete a similar venture in 1972 and again in 1978. However, for the most part, this book contains original space art based on up to the date (mid-2003) space science. The final phrase of the title, that is, the challenge of the stars, is not the challenge of making the illustrations, but more the challenge to send people to view them. Here lies one of the main reasons for the authors to prepare another space art book. That is, they wanted to further encourage people to explore space. They believe that there is a real chance that our current opportunity may slip out of our grasp and not return for a very long time. And there is no deception on their belief in this.

There are a number of pleasantries for me, in reading this book. It is non-partisan. There are no flags, no corporate logos and no sales pitch. I also like the author’s ability to step outside the box of predefined life systems. For instance, one sees oxygen-filled sacs that are alive and congregate into rafts or mature into free floating spheres. All imagines have annotations and fall within a chapter of related prose so you always know the subject of the image. Missing however, is a description of how they translate hard scientific data into images. This information would have lent authenticity to the displayed views.

Allowing an artistic mind to travel the realms of space should always result in surreal results. With David Hardy driving the illustrations and Patrick Moore co-piloting via the prose, a reader gets a visual treat that is not so much a trick as just a well thought out gallery of space art. If you are curious about what an asteroid might look like at the moment it strikes the Earth’s surface or see the birth pangs of a new star, then Futures – 50 Years in Space, The Challenge of the Stars is for you.

To read more reviews, or order the book online, visit Amazon.com.

Review by Mark Mortimer

Posted on by Fraser Cain

Station’s New Sunroom Arrives in Florida

The world’s ultimate observation deck, a control tower for robotics in space, and a sunroom like no other, has arrived at NASA’s Kennedy Space Center (KSC). It is bound for the International Space Station.

Built in Italy for the United States segment of the Station, the Cupola traveled part way around the world to reach KSC. One day it will circle the Earth every 90 minutes, and crewmembers will peer through its 360-degree windows. It will serve as a literal skylight to control some of the most sophisticated robotics ever built.

“The Cupola module will be a fascinating addition to the Space Station,” said International Space Station Program Manager Bill Gerstenmaier. “The crew will have an improved view of critical activities outside the Station and breathtaking views of the Earth below.”

The crew will use Cupola windows, six around the sides and one on the top, for line-of-sight monitoring of outside activities, including spacewalks, docking operations and exterior equipment surveys. The Cupola will be used specifically to monitor the approach and berthing of the Japanese H-2 supply craft and other visiting vehicles. The Cupola will serve as the primary location for controlling Canadarm2, the 60-foot Space Station robotic arm.

Space Station crews use two robotic control workstations in the Destiny laboratory to operate the arm. One of the robotic control stations will be placed inside the Cupola. The view from the Cupola will enhance an arm operator’s situational awareness, supplementing television cameras and graphics.

Construction of the Cupola by Alenia Spazio, under a contract with the European Space Agency (ESA), is finished. It was delivered to KSC on Oct. 7, where it will undergo acceptance testing and launch preparations.

After initial inspections conducted in the Space Station Processing Facility, the Cupola was secured inside its transportation container for storage until launch preparations begin. Before launch, KSC and European Space Agency (ESA) engineers will conduct a joint inspection leading to the turnover of the Cupola to NASA.

The Cupola is scheduled to launch on Station assembly mission 14A (Shuttle mission STS-133) in early 2009. It will be installed on the forward port of Node 3, a connecting module to be installed in 2008. The Cupola was provided by ESA to NASA as part of a barter agreement. The agreement covers launch of external payloads on the Shuttle for installation on the External Facility of the European Columbus research module.

Original Source: NASA News Release

Posted on by Fraser Cain

Spitzer Finds New Globular Cluster Nearby

Just when astronomers thought they might have dug up the last of our galaxy’s “fossils,” they’ve discovered a new one in the galactic equivalent of our own backyard.

Called globular clusters, these ancient bundles of stars date back to the birth of our Milky Way galaxy, 13 or so billion years ago. They are sprinkled around the center of the galaxy like seeds in a pumpkin. Astronomers use clusters as tools for studying the Milky Way’s age and formation.

New infrared images from NASA’s Spitzer Space Telescope and the University of Wyoming Infrared Observatory reveal a never-before-seen globular cluster within the dusty confines of the Milky Way. The findings will be reported in an upcoming issue of the Astronomical Journal.

“It’s like finding a long-lost cousin,” said Dr. Chip Kobulnicky, a professor of physics and astronomy at the University of Wyoming, Laramie, and lead author of the report. “We thought all the galaxy’s globular clusters had already been found.”

“I couldn’t believe what I was seeing,” said Andrew Monson, a graduate student at the University of Wyoming, who first spotted the cluster. “I certainly wasn’t expecting to find such a cluster.”

The newfound cluster is one of about 150 known to orbit the center of the Milky Way. These tightly packed knots of stars are among the oldest objects in our galaxy, having formed about 10 to 13 billion years ago. They contain several hundred thousand stars, most of which are older and less massive than our Sun.

Monson first noticed the cluster while scanning data from the Spitzer Space Telescope’s Galactic Legacy Infrared Mid-Plane Survey Extraordinaire – a survey to find objects hidden within the dusty mid-plane of our galaxy. He then searched archival data for a match and found only one undocumented image of the cluster from a previous NASA-funded infrared survey of the sky, called the Two Micron All-Sky Survey. “The cluster was there in the data but nobody had found it,” said Monson.

“This discovery demonstrates why Spitzer is so powerful – it can see objects that are completely hidden in visible light,” said Dr. Michael Werner of NASA’s Jet Propulsion Laboratory, Pasadena, Calif., project scientist for Spitzer. “This is particularly relevant to the study of the plane of our galaxy, where dust blocks most visible light.”

Follow-up observations with the University of Wyoming Infrared Observatory helped set the distance of the new cluster at about 9,000 light-years from Earth – closer than most clusters — and set the mass at the equivalent of 300,000 Suns. The cluster’s apparent size, as viewed from Earth, is comparable to a grain of rice held at arm’s length. It is located in the constellation Aquila.

The research team consists of astronomers from the University of Wisconsin, Madison; Boston University, Boston, Mass.; the University of Maryland, College Park, Md.; the University of Minnesota, Twin Cities; the Space Science Institute, Boulder, Colo.; and the Spitzer Science Center, Pasadena, Calif. The Galactic Legacy Infrared Mid-Plane Survey Extraordinaire is managed by the University of Wisconsin and led by Dr. Ed Churchwell.

JPL manages the Spitzer Space Telescope mission for NASA’s Science Mission Directorate, Washington, D.C. Science operations are conducted at the Spitzer Science Center at the California Institute of Technology in Pasadena. JPL is a division of Caltech. Spitzer’s infrared array camera, which captured the new cluster, was built by NASA Goddard Space Flight Center, Greenbelt, Md. The camera’s development was led by Dr. Giovanni Fazio of Harvard-Smithsonian Center for Astrophysics, Cambridge, Mass.

Additional information about the Spitzer Space Telescope is available at http://www.spitzer.caltech.edu. Additional information about the University of Wyoming Infrared Observatory is available at http://physics.uwyo.edu/~mpierce/WIRO/.

Original Source: NASA/JPL News Release

Posted on by Fraser Cain

Spacecraft Designer Maxime Faget Passes Away

Image credit: NASA
The man who designed the original spacecraft for Project Mercury and is credited with contributing to the designs of every U.S. human spacecraft from Mercury to the Space Shuttle has died. Dr. Maxime A. Faget, who in 1958 became part of the Space Task Group that would later evolve into the NASA Johnson Space Center, died Saturday at his home in Houston. He was 83 years old.

“Without Max Faget’s innovative designs and thoughtful approach to problem solving, America’s space program would have had trouble getting off the ground,” said NASA Administrator Sean O’Keefe. “He also was an aeronautics pioneer. In fact, it was his work on supersonic flight research that eventually led to his interest in space flight. The thoughts and prayers of the entire agency are with his family.”

Faget’s career with NASA dates back to 1946, when he joined the staff of Langley Research Center, Hampton, Va., as a research scientist. He worked in the Pilotless Aircraft Research Division and later was named head of the Performance Aerodynamics Branch. He conceived and proposed the development of the one-man spacecraft used in Project Mercury.

Faget was selected as one of the original 35 engineers as a nucleus of the Space Task Group to carry out the Mercury project. The group also devoted a lot of time to follow-on programs and Faget led the initial design and analysis teams that studied the feasibility of a flight to the Moon. As a result of his work and other NASA research, President John F. Kennedy was able to commit the U.S. to a lunar landing by the end of the 1960s.

“Max was a genuine icon,” said NASA’s Associate Administrator for Space Operations William Readdy, “a down-to-earth Cajun with a very nuts-and-bolts approach to engineering. He contributed immeasurably to America’s successes in human space flight. His genius allowed us to compete and win the space race to the Moon.”

“Max Faget was truly a legend of the manned space flight program,” said Christopher C. Kraft, former Johnson Space Center director. “He was a true icon of the space program. There is no one in space flight history in this or any other country who has had a larger impact on man’s quest in space exploration. He was a colleague and a friend I regarded with the highest esteem. History will remember him as one of the really great scientists of the 20th Century.”

Faget was part of the original feasibility study for the Space Shuttle. His team then focused on Shuttle development. He retired from NASA in 1981 following the second shuttle mission (STS-2). His government service career spanned four decades.

After retiring from NASA, Faget was among the founders of one of the early private space companies, Space Industries Inc., established in 1982. One of its projects was the Wake Shield Facility, built for the University of Houston and flown twice aboard the Space Shuttle to demonstrate a technique for processing material in a near-perfect vacuum.

Born on August 26, 1921, in Stann Creek, British Honduras, Faget graduated from Louisiana State University with a Bachelor of Science degree in mechanical engineering in 1943. He joined the U.S. Navy where he saw considerable combat as an officer in the submarine service.

Faget’s numerous accomplishments include patents on the “Aerial Capsule Emergency Separation Device” (escape tower), the “Survival Couch,” the “Mercury Capsule,” and a “Mach Number Indicator.”

He received numerous honors and awards, including the Arthur S. Flemming Award, the NASA Medal for Outstanding Leadership, and honorary doctorate of engineering degrees from the University of Pittsburgh and Louisiana State University. He was inducted into the National Space Hall of Fame in 1969 and the National Inventors Hall of Fame in 2003. Faget was the first recipient of the Rotary National Award for Space Achievement in 1987.

Faget was preceded in death by his wife Nancy in 1994. He is survived by four children: Ann, Carol, Guy, and Nanette; a daughter in law, two sons in law and 10 grandchildren. Funeral arrangements are pending.

Original Source: NASA News Release

Posted on by Fraser Cain

Dust Obscured Martian Landscape

This image, taken by the High Resolution Stereo Camera (HRSC) on board ESA?s Mars Express spacecraft, shows a part of the southern highlands of Mars, called Promethei Terra.

The image was taken during orbit 368 in May 2004 with a ground resolution of approximately 14 metres per pixel. The displayed region is centred around longitude 118? East and latitude 42? South.

It shows an area in the Promethei Terra region, east of the Hellas Planitia impact basin. The smooth surface is caused by a layer of dust or volcanic ash that is up to several tens of metres thick.

This layer has covered all landforms, and even young impact craters have lost their contours due to in-fill and collapse of their fragile crater walls. This layer has been removed by the wind at some ridges and crater walls.

Although the image was taken at high resolution and show very fine detail, this covering layer leads to a slightly fuzzy appearance.

The large impact crater in the southern part of the image is 32 kilometres wide and up to 1200 metres deep. The dark crater floor is most likely the result of ?deflation?, the geological term for the lifting and removal of loose material.

The dust removed here has accumulated in the southern part of the crater, forming a thick layer. The numerous dark tracks to the north-western and west are ?dust devil? tracks.

These atmospheric ?eddies?, like tornadoes on Earth, remove the uppermost dust layers which have a slightly different colour to the now-exposed surface. The tracks can be more than 20 kilometres long and contrast prominently with the lighter-coloured surroundings.

Dust devil tracks provide short-lived evidence of the ongoing geological and atmospheric activity on Mars, which consists mainly of the transport of dust by wind.

Another sign for this ?aeolian? (wind-related) activity in the area is the existence of small dune fields that have formed in some of the depressions. They can be seen in the crater in the north and in its surroundings (see close-up).

The dust devils are not limited by geomorphological boundaries: for example, their tracks cross the crater rim. Dust devil tracks can also be seen on the thick dust layer in the southern part of the crater.

Due to the thickness of the dust layer, no darker material is exposed here. The dust devil tracks show two distinct directions of movement: east to west and south-east to north-west.

Original Source: ESA News Release

Posted on by Fraser Cain

Radio Telescopes Around the World Combine in Real Time

European and US radio astronomers have demonstrated a new way of observing the Universe – through the Internet!

Using cutting-edge technology, the researchers have managed to observe a distant star by using the world’s research networks to create a giant virtual telescope. The process has allowed them to image the object with unprecedented detail, in real-time; something which only a few years ago would have been impossible. The star chosen for this remarkable demonstration, called IRC+10420, is one of the most unusual in the sky. Surrounded by clouds of dusty gas and emitting strongly in radio waves, the object is poised at the end of its life, heading toward a cataclysmic explosion known as a ‘supernova’.

These new observations give an exciting glimpse of the future of radio astronomy. Using research networks, not only will radio astronomers be able to see deeper into the distant Universe, they’ll be able to capture unpredictable, transient events as they happen, reliably and quickly.

Astronomers are always seeking to maximise the resolution of their telescopes. Resolution is a measure of the amount of detail it can pick out. The bigger the telescope, the better the resolution. VLBI (or Very Long Baseline Interferometry) is a technique used by radio astronomers to image the sky in supreme detail. Instead of using a single radio dish, arrays of telescopes are linked together across whole countries or even continents. When the signals are combined in a specialised computer, the resulting image has a resolution equal to that of a telescope as large as the maximum antenna separation.

In the past, the VLBI technique was severely hampered because the data had to be recorded onto tape and then shipped to a central processing facility for analysis. Consequently, radio astronomers were unable to judge the success of their endeavours until many weeks, even months, after the observations were made. The solution, to link the telescopes electronically in real-time, enables astronomers to analyse the data as it happens. The technique, naturally called e-VLBI, is only possible now that high-bandwidth network connectivity is a reality.

The recent 20-hour long observations, performed on 22nd September using the European VLBI Network (EVN), involved radio telescopes in the UK, Sweden, the Netherlands, Poland and Puerto Rico. The maximum separation of the antennas was 8200 km, giving a resolution of at least 20 milliarcseconds (mas); this is about 5 times better than the Hubble Space Telescope (HST). This level of detail is equivalent to picking out a small building on the surface of the moon! The inclusion of the antenna at Arecibo, in Puerto Rico, also increased the sensitivity of the telescope array by a factor of 10. Even so, observing at a frequency of 1612 MHz, the signal from the distant star was more than a billion billion times weaker than a typical mobile phone handset!

Each telescope was connected to its country’s National Research and Education Network (NREN), and the data routed at 32 Mbits/second per telescope through GEANT, the pan-European research network, to SURFnet, the Dutch network. The data were then delivered to the Joint Institute for VLBI in Europe (JIVE), the central processing facility for the EVN in the Netherlands. There, the 9 Terabits of data were fed in real-time into a specialised supercomputer, called a ‘correlator’, and combined. The same research networks were then used to deliver the final data product directly to the astronomers who formed the image. Until the network infrastructure provided GEANT became available, astronomers were unable to transfer the huge amounts of data required for e-VLBI across the Internet. In a very real sense, the Internet itself acts like a telescope, performing the same job as the curved surfaces of the individual radio dishes. Dai Davies, General Manager of DANTE who operate GEANT, said “e-VLBI performed successfully on an intercontinental basis demonstrates in the clearest possible terms the importance of data communications networks to modern science. Research networking is fundamental to this new radio astronomy technique and it is very satisfying indeed to see the benefits that are now resulting from it”.

Although the scientific goals of the experiment were modest, these e-VLBI observations of IRC+10420 open up the possibility of watching the structures of astrophysical objects as they change. IRC+10420 is a supergiant star in the constellation of Aquila. It has a mass about 10 times that of our own Sun and lies about 15,000 light years from Earth. One of the brightest infrared sources in the sky, it is surrounded by a thick shell of dust and gas thrown out from the surface of the star at a rate of about 200 times the mass of the Earth every year. Radio astronomers are able to image the dust and gas surrounding IRC+10420 because one of the component molecules, hydroxyl (OH), reveals itself by means of strong ‘maser’ emission. Essentially, the astronomers see clumps of gas where radio emission is strongly amplified by special conditions. With the zoom lens provided by e-VLBI, astronomers can make images with great detail and watch the clumps of gas move, watch masers being born and die on timescales of weeks to months, and study the changing magnetic fields that permeate the shell. The results show that the gas is moving at about 40 km/s and was ejected from the star about 900 years ago. As Prof. Phil Diamond, one of the research team at Jodrell Bank Observatory (UK), explained, “the material we’re seeing in this image left the surface of the star at around the time of the Norman Conquest of England”.

It is believed IRC+10420 is rapidly evolving toward the end of its life. At some point, maybe thousands of years from now, maybe tomorrow, the star is expected to blow itself apart in one of the most energetic phenomena known in the Universe – a ‘supernova’. The resulting cloud of material will eventually form a new generation of stars and planetary systems. Radio astronomers are now poised, with the incredible power of e-VLBI, to catch the details as they happen and study the physical processes that are so important to the structure of our Galaxy and to life itself.

The emergent technology of e-VLBI is set to revolutionise radio astronomy. As network bandwidths increase, so too will the sensitivity of e-VLBI arrays, allowing clearer views of the furthest and faintest regions of space. Dr Mike Garrett, JIVE Director, commented, “These results provide a glimpse of the enormous potential of e-VLBI. The rapid progress in global communications networks should permit us to connect together the largest radio telescopes in the world at speeds exceeding tens of Gigabits per second over the next few years. The death throes of the first massive stars in the Universe, the emerging jets of matter from the central black-holes of the first galaxies, will be revealed in exquisite detail.”

Original Source: Jodrell Bank News Release

Posted on by Fraser Cain

Rovers Still Turning Up Water Evidence

NASA’s Spirit and Opportunity have been exploring Mars about three times as long as originally scheduled. The more they look, the more evidence of past liquid water on Mars these robots discover. Team members reported the new findings at a news briefing today.

About six months ago, Opportunity established that its exploration area was wet a long time ago. The area was wet before it dried and eroded into a wide plain. The team’s new findings suggest some rocks there may have gotten wet a second time, after an impact excavated a stadium sized crater.

Evidence of this exciting possibility has been identified in a flat rock dubbed “Escher” and in some neighboring rocks near the bottom of the crater. These plate-like rocks bear networks of cracks dividing the surface into patterns of polygons, somewhat similar in appearance to cracked mud after the water has dried up here on Earth.

Alternative histories, such as fracturing by the force of the crater-causing impact, or the final desiccation of the original wet environment that formed the rocks, might also explain the polygonal cracks. Rover scientists hope a lumpy boulder nicknamed “Wopmay,” Opportunity’s next target for inspection, may help narrow the list of possible explanations.

“When we saw these polygonal crack patterns, right away we thought of a secondary water event significantly later than the episode that created the rocks,” said Dr. John Grotzinger. He is a rover-team geologist from the Massachusetts Institute of Technology, Cambridge, Mass. Finding geological evidence about watery periods in Mars’ past is the rover project’s main goal, because such persistently wet environments may have been hospitable to life.

“Did these cracks form after the crater was created? We don’t really know yet,” Grotzinger said.

If they did, one possible source of moisture could be accumulations of frost partially melting during climate changes, as Mars wobbled on its axis of rotation, in cycles of tens of thousands of years. According to Grotzinger, another possibility could be the melting of underground ice or release of underground water in large enough quantity to pool a little lake within the crater.

One type of evidence Wopmay could add to the case for wet conditions after the crater formed would be a crust of water-soluble minerals. After examining that rock, the rover team’s plans for Opportunity are to get a close look at a tall stack of layers nicknamed “Burns Cliff” from the base of the cliff. The rover will then climb out of the crater and head south to the spacecraft’s original heat shield and nearby rugged terrain, where deeper rock layers may be exposed.

Halfway around Mars, Spirit is climbing higher into the “Columbia Hills.” Spirit drove more than three kilometers (approximately two miles) across a plain to reach them. After finding bedrock that had been extensively altered by water, scientists used the rover to look for relatively unchanged rock as a comparison for understanding the area’s full range of environmental changes. Instead, even the freshest-looking rocks examined by Spirit in the Columbia Hills have shown signs of pervasive water alteration.

“We haven’t seen a single unaltered volcanic rock, since we crossed the boundary from the plains into the hills, and I’m beginning to suspect we never will,” said Dr. Steve Squyres of Cornell University, Ithaca, N.Y., principal investigator for the science payload on both rovers. “All the rocks in the hills have been altered significantly by water. We’re having a wonderful time trying to work out exactly what happened here.”

More clues to deciphering the environmental history of the hills could lie in layered rock outcrops farther upslope, Spirit’s next targets. “Just as we worked our way deeper into the Endurance crater with Opportunity, we’ll work our way higher and higher into the hills with Spirit, looking at layered rocks and constructing a plausible geologic history,” Squyres said.

Jim Erickson, rover project manager at JPL, said, “Both Spirit and Opportunity have only minor problems, and there is really no way of knowing how much longer they will keep operating. However we are optimistic about their conditions, and we have just been given a new lease on life for them, a six-month extended mission that began Oct. 1. The solar power situation is better than expected, but these machines are already well past their design life. While they’re healthy, we’ll keep them working as hard as possible.”

JPL, a division of the California Institute of Technology in Pasadena, manages the Mars Exploration Rover project for NASA’s Science Mission Directorate, Washington. Images and additional information about the project are available from JPL and Cornell at http://marsrovers.jpl.nasa.gov and http://athena.cornell.edu.

Original Source: NASA/JPL News Release