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

Posted on by Fraser Cain

Motion of Material in the Early Universe

Cosmologists from the California Institute of Technology have used observations probing back to the remote epoch of the universe when atoms were first forming to detect movements among the seeds that gave rise to clusters of galaxies. The new results show the motion of primordial matter on its way to forming galaxy clusters and superclusters. The observations were obtained with an instrument high in the Chilean Andes known as the Cosmic Background Imager (CBI), and they provide new confidence in the accuracy of the standard model of the early universe in which rapid inflation occurred a brief instant after the Big Bang.

The novel feature of these polarization observations is that they reveal directly the seeds of galaxy clusters and their motions as they proceeded to form the first clusters of galaxies.

Reporting in the October 7 online edition of Science Express, Caltech’s Rawn Professor of Astronomy, and principal investigator on the CBI project, Anthony Readhead and his team say the new polarization results provide strong support for the standard model of the universe as a place in which dark matter and dark energy are much more prevalent than everyday matter as we know it, which poses a major problem for physics. A companion paper describing early polarization observations with the CBI has been submitted to the Astrophysical Journal.

The cosmic background observed by the CBI originates from the era just 400,000 years after the Big Bang and provides a wealth of information on the nature of the universe. At this remote epoch none of the familiar structures of the universe existed–there were no galaxies, stars, or planets. Instead there were only tiny density fluctuations, and these were the seeds out of which galaxies and stars formed under the hand of gravity.

Instruments prior to the CBI had detected fluctuations on large angular scales, corresponding to masses much larger than superclusters of galaxies. The high resolution of the CBI allowed the seeds of the structures we observe around us in the universe today to be observed for the first time in January 2000.

The expanding universe cooled and by 400,000 years after the Big Bang it was cool enough for electrons and protons to combine to form atoms. Prior to this time photons could not travel far before colliding with an electron, and the universe was like a dense fog, but at this point the universe became transparent and since that time the photons have streamed freely across the universe to reach our telescopes today, 13.8 billion years later. Thus observations of the microwave background provide a snapshot of the universe as it was just 400,000 years after the Big Bang–long before the formation of the first galaxies, stars, and planets.

The new data were collected by the CBI between September 2002 and May 2004, and cover four patches of sky, encompassing a total area three hundred times the size of the moon and showing fine details only a fraction of the size of the moon. The new results are based on a property of light called polarization. This is a property that can be demonstrated easily with a pair of polarizing sunglasses. If one looks at light reflected off a pond through such sunglasses and then rotates the sunglasses, one sees the reflected light varying in brightness. This is because the reflected light is polarized, and the polarizing sunglasses only transmit light whose polarization is properly aligned with the glasses. The CBI likewise picks out the polarized light, and it is the details of this light that reveal the motion of the seeds of galaxy clusters.

In the total intensity we see a series of peaks and valleys, where the peaks are successive harmonics of a fundamental “tone.” In the polarized emission we also see a series of peaks and valleys, but the peaks in the polarized emission coincide with the valleys in the total intensity, and vice versa. In other words, the polarized emission is exactly out of step with the total intensity. This property of the polarized emission being out of step with the total intensity indicates that the polarized emission arises from the motion of the material.

The first detection of polarized emission by the Degree Angular Scale Interferometer (DASI), the sister project of the CBI, in 2002 provided dramatic evidence of motion in the early universe, as did the measurements by the Wilkinson Microwave Anisotropy Probe (WMAP) in 2003. The CBI results announced today significantly augment these earlier findings by demonstrating directly, and on the small scales corresponding to galaxy clusters, that the polarized emission is out of step with the total intensity.

Other data on the cosmic microwave background polarization were released just two weeks ago by the DASI team, whose three years of results show further compelling evidence that the polarization is indeed due to the cosmic background and is not contaminated by radiation from the Milky Way. The results of these two sister projects therefore complement each other beautifully, as was the intention of Readhead and John Carlstrom, the principal investigator of DASI and a coauthor on the CBI paper, when they planned these two instruments a decade ago.

According to Readhead, “Physics has no satisfactory explanation for the dark energy which dominates the universe. This problem presents the most serious challenge to fundamental physics since the quantum and relativistic revolutions of a century ago. The successes of these polarization experiments give confidence in our ability to probe fine details of the polarized cosmic background, which will eventually throw light on the nature of this dark energy.”

“The success of these polarization experiments has opened a new window for exploring the universe which may allow us to probe the first instants of the universe through observations of gravitational waves from the epoch of inflation,” says Carlstrom.

The analysis of the CBI data is carried out in collaboration with groups at the National Radio Astronomy Observatory (NRAO) and at the Canadian Institute for Theoretical Astrophysics (CITA).

“This is truly an exciting time in cosmological research, with a remarkable convergence of theory and observation, a universe full of mysteries such as dark matter and dark energy, and a fantastic array of new technology–there is tremendous potential for fundamental discoveries here” says Steve Myers of the NRAO, a coauthor and key member of the CBI team from its inception.

According to Richard Bond, director of CITA and a coauthor of the paper, “As a theorist in the early eighties, when we were first showing that the magnitude of the cosmic microwave background polarization would likely be a factor of a hundred down in power from the minute temperature variations that were themselves a heroic effort to discover, it seemed wishful thinking that even in some far distant future such minute signals would be revealed. With these polarization detections, the wished-for has become reality, thanks to remarkable technological advances in experiments such as CBI. It has been our privilege at CITA to be fully engaged as members of the CBI team in unveiling these signals and interpreting their cosmological significance for what has emerged as the standard model of cosmic structure formation and evolution.”

The next step for Readhead and his CBI team will be to refine these polarization observations significantly by taking more data, and to test whether or not the polarized emission is exactly out of step with the total intensity with the goal of finding some clues to the nature of the dark matter and dark energy.

The CBI is a microwave telescope array comprising 13 separate antennas, each about three feet in diameter and operating in 10 frequency channels, set up in concert so that the entire instruments acts as a set of 780 interferometers. The CBI is located at Llano de Chajnantor, a high plateau in Chile at 16,800 feet, making it by far the most sophisticated scientific instrument ever used at such high altitudes. The telescope is so high, in fact, that members of the scientific team must each carry bottled oxygen to do the work.

The upgrade of the CBI to polarization capability was supported by a generous grant from the Kavli Operating Institute, and the project is also the grateful recipient of continuing support from Barbara and Stanley Rawn Jr. The CBI is also supported by the National Science Foundation, the California Institute of Technology, and the Canadian Institute for Advanced Research, and has also received generous support from Maxine and Ronald Linde, Cecil and Sally Drinkward, and the Kavli Institute for Cosmological Physics at the University of Chicago.

In addition to the scientists mentioned above, today’s Science Express paper is coauthored by C. Contaldi and J. L. Sievers of CITA, J.K. Cartwright and S. Padin, both of Caltech and the University of Chicago; B. S. Mason and M. Pospieszalski of the NRAO; C. Achermann, P. Altamirano, L. Bronfman, S. Casassus, and J. May all of the University of Chile; C. Dickinson, J. Kovac, T. J. Pearson, and M. Shepherd of Caltech; W. L. Holzapfel of UC Berkeley; E. M. Leitch and C. Pryke of the University of Chicago; D. Pogosyan of the University of Toronto and the University of Alberta; and R. Bustos, R. Reeves, and S. Torres of the University of Concepci?n, Chile.

Original Source: Caltech News Release

Posted on by Fraser Cain

Antarctica Is Getting Ready to Really Heat Up

While Antarctica has mostly cooled over the last 30 years, the trend is likely to rapidly reverse, according to a computer model study by NASA researchers. The study indicates the South Polar Region is expected to warm during the next 50 years.

Findings from the study, conducted by researchers Drew Shindell and Gavin Schmidt of NASA’s Goddard Institute of Space Studies (GISS), New York, appeared in the Geophysical Research Letters. Shindell and Schmidt found depleted ozone levels and greenhouse gases are contributing to cooler South Pole temperatures.

Low ozone levels in the stratosphere and increasing greenhouse gases promote a positive phase of a shifting atmospheric climate pattern in the Southern Hemisphere, called the Southern Annular Mode (SAM). A positive SAM isolates colder air in the Antarctic interior.

In the coming decades, ozone levels are expected to recover due to international treaties that banned ozone-depleting chemicals. Higher ozone in the stratosphere protects Earth’s surface from harmful ultraviolet radiation. The study found higher ozone levels might have a reverse impact on the SAM, promoting a warming, negative phase. In this way, the effects of ozone and greenhouse gases on the SAM may cancel each other out in the future. This could nullify the SAM’s affects and cause Antarctica to warm.

“Antarctica has been cooling, and one could argue some regions could escape warming, but this study finds this is not very likely,” Shindell said. “Global warming is expected to dominate in future trends.”

The SAM, similar to the Arctic Oscillation or Northern Annular Mode in the Northern Hemisphere, is a seesaw in atmospheric pressure between the pole and the lower latitudes over the Southern Ocean and the tip of South America.

These pressure shifts between positive and negative phases speed-up and slow down the westerly winds that encircle Antarctica. Since the late 1960s, the SAM has more and more favored its positive phase, leading to stronger westerly winds. These stronger westerly winds act as a kind of wall that isolates cold Antarctic air from warmer air in the lower latitudes, which leads to cooler temperatures.

Greenhouse gases and ozone depletion both lower temperatures in the high latitude stratosphere. The cooling strengthens the stratospheric whirling of westerly winds, which in turn influences the westerly winds in the lower atmosphere. According to the study, greenhouse gases and ozone have contributed roughly equally in promoting a strong-wind, positive SAM phase in the troposphere, the lowest part of the atmosphere.

Shindell and Schmidt used the NASA GISS Climate Model to run three sets of tests, each three times. For each scenario, the three runs were averaged together. Scenarios included the individual effects of greenhouse gases and ozone on the SAM, and then a third run that examined the effects of the two together.

The model included interactions between the oceans and atmosphere. Each model run began in 1945 and extended through 2055. For the most part, the simulations matched well compared with past observations.

Model inputs of increasing greenhouse gases were based upon observations through 1999, and upon the Intergovernmental Panel on Climate Change mid-range estimates of future emissions. Stratospheric ozone changes were based on earlier NASA GISS model runs that were found to be in good agreement with past observations and similar to those found in other chemistry-climate models for the future.

Shindell said the biggest long-term danger of global warming in this region would be ice sheets melting and sliding into the ocean. “If Antarctica really does warm up like this, then we have to think seriously about what level of warming might cause the ice sheets to break free and greatly increase global sea levels,” he said.

In the Antarctic Peninsula, ice sheets as big as Rhode Island have already collapsed into the ocean due to warming. The warming in this area is at least partially a result of the strengthened westerly winds that pass at latitudes of about 60 to 65 degrees south. As the peninsula sticks out from the continent, these winds carry warm maritime air that heats the peninsula.

Original Source: NASA News Release