June 21, 2009, 9:25 PM CT

A glimpse of things to come

Herschel opened its 'eyes' on 14 June and the Photoconductor Array Camera and Spectrometer obtained images of M51, 'the whirlpool galaxy' for a first test observation. Researchers obtained images in three colours which clearly demonstrate the superiority of Herschel, the largest infrared space telescope ever flown.

This image shows the famous 'whirlpool galaxy', first observed by Charles Messier in 1773, who provided the designation Messier 51 (M51). This spiral galaxy lies relatively nearby, about 35 million light-years away, in the constellation Canes Venatici. M51 was the first galaxy discovered to harbour a spiral structure.

The image is a composite of three observations taken at 70, 100 and 160 microns, taken by Herschel's Photoconductor Array Camera and Spectrometer (PACS) on 14 and 15 June, immediately after the satellite's cryocover was opened on 14 June.

Herschel, launched only a month ago, is still being commissioned and the first images from its instruments were planned to arrive only in a few weeks. But engineers and researchers were challenged to try to plan and execute daring test observations as part of a 'sneak preview' immediately after the cryocover was opened. The objective was to produce a very early image that gives a glimpse of things to come......... Posted by: Brooke      Read more         Source

April 27, 2009, 5:13 AM CT

Did dinosaurs die from an asteroid hit?

The enduringly popular theory that the Chicxulub crater holds the clue to the demise of the dinosaurs, along with some 65 percent of all species 65 million years ago, is challenged in a paper to be reported in the Journal of the Geological Society on April 27, 2009.

The crater, discovered in 1978 in northern Yucutan and measuring about 180 kilometers (112 miles) in diameter, records a massive extra-terrestrial impact.

When spherules from the impact were found just below the Cretaceous-Tertiary (K-T) boundary, it was quickly identified as the "smoking gun" responsible for the mass extinction event that took place 65 million years ago.

It was this event which saw the demise of dinosaurs, along with countless other plant and animal species.

However, many researchers have since disagreed with this interpretation.

The newest research, led by Gerta Keller of Princeton University in New Jersey, and Thierry Adatte of the University of Lausanne, Switzerland, uses evidence from Mexico to suggest that the Chicxulub impact predates the K-T boundary by as much as 300,000 years.

"Keller and his colleagues continue to amass detailed stratigraphic information supporting new thinking about the Chicxulub impact, and the mass extinction at the end of the Cretaceous," says H. Richard Lane, program director in the National Science Foundation (NSF)'s Division of Earth Sciences, which funded the research. "The two may not be linked after all"......... Posted by: William      Read more         Source

March 31, 2009, 2:52 PM CT

Ozone depletion from rocket launching

The global market for rocket launches may require more stringent regulation in order to prevent significant damage to Earth's stratospheric ozone layer in the decades to come, as per a newly released study by scientists in California and Colorado.

Future ozone losses from unregulated rocket launches will eventually exceed ozone losses due to chlorofluorocarbons, or CFCs, which stimulated the 1987 Montreal Protocol banning ozone-depleting chemicals, said Martin Ross, chief study author from The Aerospace Corporation in Los Angeles. The study, which includes the University of Colorado at Boulder and Embry-Riddle Aeronautical University, provides a market analysis for estimating future ozone layer depletion based on the expected growth of the space industry and known impacts of rocket launches.

"As the rocket launch market grows, so will ozone-destroying rocket emissions," said Professor Darin Toohey of CU-Boulder's atmospheric and oceanic sciences department. "If left unregulated, rocket launches by the year 2050 could result in more ozone destruction than was ever realized by CFCs".

A paper on the subject by Ross and Manfred Peinemann of The Aerospace Corporation, CU-Boulder's Toohey and Embry-Riddle Aeronautical University's Patrick Ross appeared online in March in the journal Astropolitics........ Posted by: Tyler      Read more         Source

January 8, 2009, 7:41 PM CT

Balloon Flight Test Over Antarctica

The National Science Foundation (NSF) and the National Aeronautics and Space Administration (NASA) have successfully launched and demonstrated a newly designed super pressure balloon prototype that will one day enable a new era of high-altitude scientific research. The super pressure balloon is expected to ultimately carry large scientific experiments to the brink of space for 100 days or more.

"This flight test of NASA's seven-million-cubic-foot super pressure balloon is a very important step forward in building a new capability for scientific ballooning based on sound engineering and operational development," said W. Vernon Jones, NASA's senior scientist for suborbital research at NASA Headquarters in Washington. "While the team has a ways to go in scaling up the pumpkin balloon to be able to lift a one-ton instrument to a float altitude of 110,000 feet, the team has demonstrated they are on the right path".

The super pressure balloon was highlighted in the National Research Council's decadal survey, "Astronomy and Astrophysics in the New Millennium," and will play an important role in providing inexpensive access to the near-space environment for science and technology.

The test flight was launched Dec. 28, 2008, from McMurdo Station, NSF's logistics hub in Antarctica. NASA and NSF conduct an annual scientific balloon campaign during the Antarctic summer. NSF manages the U.S. Antarctic Program and provides logistic support for all U.S. scientific operations in Antarctica......... Posted by: Brooke      Read more         Source

December 11, 2008, 10:31 PM CT

New detector will aid dark matter search

Several research projects are underway to try to detect particles that may make up the mysterious "dark matter" believed to dominate the universe's mass. But the existing detectors have a problem: They also pick up particles of ordinary matter -- hurtling neutrons that masquerade as the elusive dark-matter particles the instruments are designed to find.

MIT physicist Jocelyn Monroe has a solution. A new detector she and her students have built just finished its initial testing last week at Los Alamos National Laboratory. When deployed in the next few months alongside one of the existing dark-matter detectors, the new device should identify all of the ordinary neutrons that come along, leaving anything else that the other detector picks up as a strong candidate for the elusive dark matter.

"Dark matter experiments are very hard," explains Monroe, who worked on the project with undergraduates Dianna Cowern and Rick Eyers and with graduate students Shawn Henderson and Asher Kaboth. "They are looking for a tiny signal, from a phenomenon that happens very rarely," namely the collision of a dark-matter particle with one of ordinary matter, producing a tiny, brief flash of light.

Such flashes can be detected by putting a tank of liquid deep underground to shield it from most stray particles, then lining the tank with photomultiplier tubes that can pick up even the faintest bursts of light......... Posted by: Kevin      Read more         Source

December 9, 2008, 9:17 PM CT

Building telescope at South Pole

It's 40 degrees F below zero (with the wind chill) at the South Pole today. Yet a research team from the University of Delaware is taking it all in stride.

The physicists, engineers and technicians from the University of Delaware's Bartol Research Institute are part of an international team working to build the world's largest neutrino telescope in the Antarctic ice, far beneath the continent's snow-covered surface.

Dubbed "IceCube," the telescope will occupy a cubic kilometer of Antarctica when it is completed in 2011, opening super-sensitive new eyes into the heavens.

"IceCube will provide new information about some of the most violent and far-away astrophysical events in the cosmos," says Thomas Gaisser, the Martin A. Pomerantz Chaired Professor of Physics and Astronomy at the University of Delaware, and one of the project's lead scientists.

The University of Delaware is among 33 institutions worldwide that are contributing to the National Science Foundation project, which is coordinated by the University of Wisconsin.

Besides taking a turn as "on-ice lead" for this year's IceCube construction effort at the South Pole (or simply "Pole," as the locals call it), Gaisser is managing the University of Delaware's continued deployment of the telescope's surface array of detectors, known as "IceTop"......... Posted by: Tyler      Read more         Source

November 13, 2008, 10:44 PM CT

A Planet Orbiting Another Star

NASA's Hubble Space Telescope has taken the first visible-light snapshot of a planet circling another star.

Estimated to be no more than three times Jupiter's mass, the planet, called Fomalhaut b, orbits the bright southern star Fomalhaut, located 25 light-years away in the constellation Piscis Australis, or the "Southern Fish".

Fomalhaut has been a candidate for planet hunting ever since an excess of dust was discovered around the star in the early part of 1980s by NASA's Infrared Astronomy Satellite, IRAS.

In 2004, the coronagraph in the High Resolution Camera on Hubble's Advanced Camera for Surveys produced the first-ever resolved visible-light image of the region around Fomalhaut. It clearly showed a ring of protoplanetary debris approximately 21.5 billion miles across and having a sharp inner edge.

This large debris disk is similar to the Kuiper Belt, which encircles the solar system and contains a range of icy bodies from dust grains to objects the size of dwarf planets, such as Pluto.

Hubble astronomer Paul Kalas, of the University of California at Berkeley, and team members proposed in 2005 that the ring was being gravitationally modified by a planet lying between the star and the ring's inner edge.

Circumstantial evidence came from Hubble's confirmation that the ring is offset from the center of the star. The sharp inner edge of the ring is also consistent with the presence of a planet that gravitationally "shepherds" ring particles. Independent scientists have subsequently reached similar conclusions......... Posted by: Brooke      Read more         Source

September 28, 2008, 9:09 PM CT

Looking for water on Mars

NASA's Phoenix Scout Lander reached Mars on May 25,, opened a soils lab, and started looking for water. Phoenix uses a robotic scoop arm to deliver regolith samples to the suite of instruments aboard the Lander--with one exception. The thermal and electrical conductivity probe designed by a team of research researchers at Decagon Devices Inc. is actually mounted on the robotic arm and makes direct contact with the regolith. It measures thermal conductivity, thermal diffusivity, electrical conductivity, and dielectric permittivity of the regolith, as well as vapor pressure of the air.

Finding Water, Building Climate Models

Phoenix uses the probe to look for evidence of water on Mars and to determine thermal properties of the regolith for use in climate models. The data collected so far await analysis, but the numbers look intriguing and promising not just for Mars study but here on earth.

Fat Needle Challenge

Logistical challenges early on forced the Decagon team to look for flexibility in the transient heated needle technique in order to build a successful thermal properties analyzer for Mars. Phoenix's robotic arm can't insert the needles as gently as a human hand. Long, thin needles approximating an infinitely long line heat source as mandatory by the model were likely to snap when inserted into a surface of unknown hardness. The best alternative design featured stubby, conical needles which violated the assumptions of the transient heated needle theory......... Posted by: Brooke      Read more         Source

July 16, 2008, 7:51 PM CT

A new way to weigh giant black holes

How do you weigh the biggest black holes in the universe? One answer now comes from a completely new and independent technique that astronomers have developed using data from NASA's Chandra X-ray Observatory.

By measuring a peak in the temperature of hot gas in the center of the giant elliptical galaxy NGC 4649, researchers have determined the mass of the galaxy's supermassive black hole. The method, applied for the first time, gives results that are consistent with a traditional technique.

Astronomers have been seeking out different, independent ways of precisely weighing the largest supermassive black holes, that is, those that are billions of times more massive than the Sun. Until now, methods based on observations of the motions of stars or of gas in a disk near such large black holes had been used.

"This is tremendously important work since black holes can be elusive, and there are only a couple of ways to weigh them accurately," said Philip Humphrey of the University of California at Irvine, who led the study. "It's reassuring that two very different ways to measure the mass of a big black hole give such similar answers".

NGC 4649 is now one of only a handful of galaxies for which the mass of a supermassive black hole has been measured with two different methods. In addition, this new X-ray technique confirms that the supermassive black hole in NGC 4649 is one of the largest in the local universe with a mass about 3.4 billion times that of the Sun, about a thousand times bigger than the black hole at the center of our galaxy......... Posted by: Brooke      Read more         Source

Tue, 24 Jun 2008 03:43:25 GMT

Martian Skies

The atmosphere of Mars is hundreds of times thinner than Earth''s atmosphere and is made of 95% carbon dioxide, 3% nitrogen, 1.6% argon, and contains traces of oxygen, water, and methane. It can support dust storms, dust devils, clouds and gusty winds.

With an amazing number of six current live probes exploring Mars, there are many thousands of images available. Only a few, however show atmospheric phenomena. Presented here are some of the best images of Martian atmosphere in action.

Related: Martian weather report. Posted by: Gerard      Read more     Source

May 22, 2008, 10:22 PM CT

Continued turbulence in Jupiter's atmosphere

Berkeley -- Increased turbulence and storms first observed on Jupiter more than two years ago are still raging, as per astronomers from the University of California, Berkeley, and the W. M. Keck Observatory in Hawaii, who snapped high-resolution pictures of the planet earlier this month.

Captured with NASA's Hubble Space Telescope (HST) and the 10-meter Keck II telescope, this so-called "major upheaval" on Jupiter involves stunning changes in the planet's atmosphere, said lead astronomer Imke de Pater, professor of astronomy at UC Berkeley.

The images are available on NASA's Web site, http://hubblesite.org/news/2008/23.

The upheaval was heralded in December 2005 by a color change from white to red of a large oval near the Great Red Spot, earning it the moniker Red Spot Jr. This oval, formally known as Oval BA, formed six years earlier through a merger of three large white ovals just south of the Great Red Spot - storms that formed in the early 1930s and were prominent in the Voyager era.

The new images, the first since Jupiter emerged from its passage behind the Sun, may show that Jupiter indeed is undergoing a major climate change, as predicted four years ago.

"One of the most notable changes we observe in both the Hubble and Keck images is the change from a rather bland, quiescent band surrounding the Great Red Spot just over a year ago to one that is incredibly turbulent at both sides of the spot," de Pater said. "During all prior HST observations and spacecraft encounters, starting with Voyager in 1979, such turbulence was seen only on the west or left side of the spot."........ Posted by: Brooke      Read more         Source

May 11, 2008, 10:22 AM CT

Evolution of "gas giants"

By shooting the high-energy Omega laser onto precompressed samples of planetary fluids, researchers are gaining a better understanding of the evolution and internal structure of Jupiter, Saturn and extrasolar giant planets.

The properties of dense helium (He) - which happens to be a principal constituent of giant gas planets like Jupiter - at thermodynamic conditions between those of condensed matter and high-temperature plasmas are theoretically challenging and unexplored experimentally.

Laboratory researchers collaborating with scientists at the Laboratory for Laser Energetics, CEA France and UC Berkeley were able to determine the equation of state (EOS) for fluid He at pressures above 100 GPa (one million times more pressure than the Earth's atmosphere - one GPa (gigapascal) equals 10,000 atmospheres).

The only prior high temperature and pressure He EOS data available for constraining planetary models waccording toformed at LLNL by Bill Nellis and his team using a two-stage gas gun. However, those earlier experiments used cryogenic techniques at ambient pressure so their densities were significantly lower than those achieved with the precompressed samples. Also, the final pressures, 16 GPa for a single shock, were significantly lower than the new laser shock data......... Posted by: Kevin      Read more         Source

April 28, 2008, 8:27 PM CT

Satellite Mission To Map Earth's Water Cycle

MIT Professor Dara Entekhabi will lead the science team designing a NASA satellite mission to make global soil moisture and freeze/thaw measurements, data essential to the accuracy of weather forecasts and predictions of global carbon cycle and climate. NASA announced recently that the Soil Moisture Active-Passive mission (SMAP) is scheduled to launch December 2012.

At present, researchers have no network for gathering soil moisture data as they do for rainfall, winds, humidity and temperature. Instead, that data is gathered only at a few scattered points around the world.

"Soil moisture is the lynchpin of the water, energy and carbon cycles over land. It is the variable that links these three cycles through its control on evaporation and plant transpiration. Global monitoring of this variable will allow a new perspective on how these three cycles work and vary together in the Earth system," said Entekhabi, director of the Parsons Laboratory for Environmental Science and Engineering in MIT's Department of Civil and Environmental Engineering.

"Additionally because soil moisture is a state variable that controls both water and energy fluxes at the land surface, we anticipate that assimilation of the global observations will improve the skill in numerical weather prediction, particularly for events that are influenced by these fluxes at the base of the atmosphere," he said......... Posted by: Brooke      Read more         Source

March 9, 2008, 4:45 PM CT

GLAST Spacecraft Arrives in Florida

NASA's Gamma-ray Large Area Space Telescope, or GLAST, arrived Tuesday at the Astrotech payload processing facility near the Kennedy Space Center to begin final preparations for launch. Liftoff of GLAST aboard a Delta II rocket is currently targeted for 11:45 a.m. EDT on May 16.

GLAST is a collaborative mission with the U.S. Department of Energy, international partners from France, Gera number of, Italy, Japan and Sweden, and numerous academic institutions from the U.S. and abroad. The spacecraft will explore the most extreme environments in the universe, and answer questions about supermassive black hole systems, pulsars and the origin of cosmic rays. It also will study the mystery of powerful explosions known as gamma-ray bursts.

The milestones to be accomplished over the next two months include attaching the Ku-band communications antenna and the two sets of solar arrays, a complete checkout of GLAST's scientific instruments, installing the spacecraft's battery, and loading aboard the observatory's propellant. These activities will be performed by General Dynamics, builder of the spacecraft for NASA. GLAST currently is scheduled to be transported to Pad 17-B at Cape Canaveral Air Force Station on May 1.

The rocket that will launch GLAST is a Delta II 7920-H, manufactured and prepared for launch by United Launch Alliance. It is a heavier-lift model of the standard Delta II that uses larger solid rocket boosters. The first stage is scheduled to be erected on Pad 17-B the week of March 17......... Posted by: Brooke      Read more         Source

March 9, 2008, 4:43 PM CT

Canadian astronomers on hunt for meteor

Astronomers from The University of Western Ontario in London, Ontario, have captured rare video of a meteor falling to Earth.

The Physics and Astronomy Department at Western has a network of all-sky cameras in Southern Ontario that scan the sky monitoring for meteors. Associate Professor Peter Brown, who specializes in the study of meteors and meteorites, says that Wednesday evening (March 5) at 10:59 p.m. EST these cameras captured video of a large fireball and the department has also received many calls and emails from people who actually saw the light.

Brown along with Wayne Edwards, a post doctorate student, hope to enlist the help of local residents in recovering one or more possible meteorites that may have crashed in the Parry Sound area.

Most meteoroids burn up by the time they hit an altitude of 60 or 70 kilometres from Earth, says Edwards. We tracked this one to an altitude of about 24 kilometres so we are pretty sure there are at least one, and possibly a number of meteorites, that made it to the ground.

Edwards says the lab can narrow the ground location where the meteorite would have fallen, to about 12 square kilometres and have created a map that may assist in locating the meteorite. The rock, or rocks, would probably weigh a kilogram or slightly more......... Posted by: Brooke      Read more         Source

February 24, 2008, 10:25 PM CT

The light and dark of Venus

Venus Express has revealed a planet of extraordinarily changeable and extremely large-scale weather. Bright hazes appear in a matter of days, reaching from the south pole to the low southern latitudes and disappearing just as quickly. Such 'global weather', unlike anything on Earth, has given researchers a new mystery to solve.

The cloud-covered world of Venus is all but a featureless, unchangeable globe at visible wavelengths of light. Switch to the ultraviolet and it reveals a truly dynamic nature. Transient dark and bright markings stripe the planet, indicating regions where solar ultraviolet radiation is absorbed or reflected, respectively.

Venus Express watches the behaviour of the planet's atmosphere with its Venus Monitoring Camera (VMC). It has seen some amazing things. In July 2007, VMC captured a series of images showing the development of the bright southern haze. Within days, the high-altitude veil continually brightened and dimmed, moving towards equatorial latitudes and back towards the pole again.

Such global weather suggests that fast dynamical, chemical and microphysical processes are at work on the planet. During these episodes, the brightness of the southern polar latitudes increased by about a third and faded just as quickly, as sulphuric acid particles coagulate......... Posted by: Brooke      Read more         Source

January 14, 2008, 3:19 PM CT

Pulses in Saturn's rings

In 2005, the Cassini spacecraft began a series of experiments to profile ring structure and measure the size distribution of particles in Saturn's rings. During these experiments, Cassini flew behind the ring plane and transmitted radio waves through ring particles to Earth. Researchers on Earth analyzed the signals' diffraction patterns to help determine properties of the rings. Thomson et al.

Typically study these data and find that in limited regions of rings a and b (a and b lie close to the outside of saturn's ring system), the diffraction pattern reveals the presence of fine-scale structures that are characterized by periodic radial variation in optical depth. They define specific periods of variation in optical depth for distinct regions of rings A and B. Past research suggests that the dynamic interplay of gravitational and collisional forces leads to the formation of viscous oscillations and gravity wakes in Saturn's rings. The authors speculate that the number density of ring particles contracts and relaxes to form periodic structures that affect the radio signals seen on Earth......... Posted by: Brooke      Read more         Source

November 29, 2007, 10:53 PM CT

Youngest solar systems detected

ANN ARBOR, Mich.---Astronomers at the University of Michigan have found what are thought to besome of the youngest solar systems yet detected.

The systems are around the young stars UX Tau A and LkCa 15, located in the Taurus star formation region just 450 light years away. Using a telescope that measures levels of infrared radiation, the scientists noticed gaps in the protoplanetary disks of gas and dust surrounding these stars. They say those gaps are most likely caused by infant planets sweeping those areas clear of debris.

A paper on the findings by astronomy doctoral student Catherine Espaillat, professor Nuria Calvet, and their colleagues is reported in the Dec. 1 issue of Astrophysical Journal Letters.

"Previously, astronomers were seeing holes at the centers of protoplanetary disks and one of the theories was that the star could be photoevaporating that material," said Espaillat, first author of the paper.

Photoevaporation refers to the process of heating up the dust and gas in the surrounding cloud until it evaporates and dissipates.

"We observed that in some stars, including these two, instead of a hole, there's a gap," Espaillat said. "It's more like a lane has been cleared within the disk. That is not consistent with photoevaporation. The existence of planets is the most probable theory that can explain this structure"......... Posted by: Brooke      Read more         Source

November 13, 2007, 9:28 PM CT

Regional variation in warming from sun

A NASA satellite designed, built and controlled by the University of Colorado at Boulder is expected to help researchers resolve wide-ranging predictions about the coming solar cycle peak in 2012 and its influence on Earth's warming climate, as per the chief scientist on the project.

Senior Research Associate Tom Woods of CU-Boulder's Laboratory for Atmospheric and Space Physics said the brightening of the sun as it approaches its next solar cycle maximum will have regional climatic impacts on Earth. While some researchers predict the next solar cycle -- expected to start in 2008 -- will be significantly weaker than the present one, others are forecasting an increase of up to 40 percent in the sun's activity, said Woods.

Woods is the principal investigator on NASA's $88 million Solar Radiation and Climate Experiment, or SORCE, mission, launched in 2003 to study how and why variations in the sun affect Earth's atmosphere and climate. In August, NASA extended the SORCE mission through 2012. The extension provides roughly $18 million to LASP, which controls SORCE from campus by uploading commands and downloading data three times daily to the Space Technology Building in the CU Research Park.

Solar cycles, which span an average of 11 years, are driven by the amount and size of sunspots present on the sun's surface, which modulate brightness from the X-ray to infrared portion of the electromagnetic spectrum. The current solar cycle peaked in 2002......... Posted by: Tyler      Read more         Source

November 1, 2007, 8:26 PM CT

Phoenix:Tasks En Route to Mars Include Course Tweak, Gear Checks

NASA's Phoenix Mars Lander, launched on Aug. 4 and headed to Mars, fired its four trajectory correction thrusters Wednesday for only the second time. The 45.9-second burn nudged the spacecraft just the right amount to put it on a course to arrive at the red planet seven months from today.

At Mars, Phoenix will face a challenging 7-minute descent through the atmosphere to land in the far north on May 25, 2008. After landing, it will use a robotic digging arm and other instruments during a three-month period to investigate whether icy soil of the Martian arctic could have ever been a favorable environment for microbial life. The solar-powered lander will also look for clues about the history of the water in the ice and will monitor weather as northern Mars' summer progresses toward fall.

The second course adjustment had been postponed a week to allow time for carefully returning the spacecraft to full operations after a cosmic-ray strike disrupted a computer memory chip Oct. 6. Experiences with prior spacecraft have shown hits by cosmic rays are a known hazard in deep space. The Phoenix spacecraft properly followed its onboard safety programming by putting itself into a precautionary standby state when the event occurred. Mission controllers then followed step-by-step procedures to understand the cause and resume regular operations......... Posted by: Brooke      Read more         Source

October 28, 2007, 4:18 PM CT

Mars With Ice, Shaken, Not Stirred

Mars, like Earth, is a climate-fickle water planet. The main difference, of course, is that water on the frigid Red Planet is rarely liquid, preferring to spend almost all of its time traveling the world as a gas or churning up the surface as ice. That's the global picture literally and figuratively coming into much sharper focus as various Mars-orbiting cameras send back tomes of unprecedented super high-resolution imagery of ever vaster tracts of the planet's surface.

What were just a few years ago small hints about Mars' water and climate, as seen in a few "postage-stamp" high-resolution images and topography, have given way to broader theory that explains not only the features seen on the planet today, but imply a dynamic history of Martian climate change.

"When you have postage stamps, it's like studying a hair on an arm instead of the whole arm," said Mars researcher James Head III of Brown University. Head will present the latest integrated global view of Martian surface features and how they fit with Martian climate models on Sunday, 28 October 2007, at the Geological Society of America Annual Meeting in Denver.

The pictures now reveal a range of ice-made features that show a strong preference to certain latitudes, Head explains. As on Earth, latitude-dependent features can mean only one thing: latitude-dependent climate......... Posted by: Brooke      Read more         Source

October 24, 2007, 7:31 PM CT

First-Known Belt Of Moonlets In Saturn Rings

A narrow belt harboring moonlets as large as football stadiums discovered in Saturn's outermost ring probably resulted when a larger moon was shattered by a wayward asteroid or comet eons ago, as per a University of Colorado at Boulder study.

Images taken by a camera onboard the NASA Cassini spacecraft revealed a series of eight propeller-shaped "wakes" in a thin belt of the outermost "A" ring, indicating the presence of corresponding moonlets, said CU-Boulder Research Associate Miodrag Sremcevic, lead author of the study reported in the Oct. 25 issue of Nature. The propeller wakes highlight tiny areas of the belt where ring material has been perturbed by the gravitational forces caused by individual moonlets, Sremcevic said.

The team calculated that there likely are thousands of moonlets ranging in size from semi-trailers to sports arenas embedded in the "A" ring's thin moonlet belt that circles the planet. At about 2,000 miles across, the belt of moonlets is only about 1/80th the diameter of Saturn's total ring system, which at roughly 155,000 miles across would stretch about two-thirds of the way from Earth to the moon.

"This is the first evidence of a moonlet belt in any of Saturn's rings," said Sremcevic of CU-Boulder's Laboratory for Atmospheric and Space Physics. "We have firmly established these moonlets exist in a relatively narrow region of the "A" ring, and the evidence indicates they are remnants of a larger moon that was shattered by a meteoroid or comet."........ Posted by: Brooke      Read more         Source

October 8, 2007, 9:28 AM CT

Satellite methods for monitoring volcanic activity

The central part of the Andes situated between southern Peru and Chile bears 50 active or potentially volcanoes, spread along a 1500 km-long arc. These volcanic structures mostly rise to between 4000 and 7000 m, are very remote with abrupt slopes and are often cloaked in snow. Few studies have been made on them as such conditions make field surveying extremely difficult. A team of IRD scientists working in partnership with the University of Chile (Santiago) and the Observatoire de Physique du Globe of Clermont-Ferrand (1) focused special attention on the Lastarria-Cordon del Azufre volcanic complex. With a surface area of 1600 km, it is situated in the central Andes Cordillera at the border between Argentina and Chile near Antofagasta.

Research projects on deformations of the earth crust, conducted in this region between 1992 and 2000 by a North American team, had led to the detection of a long wavelength signal over the areas topography, extracted from analysis of data collected by the European Space Agency (ESA) satellite ERS-1. This deformation would correspond to crustal inflation affecting the whole Lastarria-Cordon del Azufre complex. Eventhough this volcano is not considered as active, as the last eruption dates back 9000 years, such inflation could express an underlying activity correlation to the dynamics of a functioning magma chamber......... Posted by: Tyler      Read more         Source

October 2, 2007, 10:22 PM CT

Light on mysterious 'dark matter'

Weve all been taught that our bodies, the Earth, and in fact all matter in the universe is composed of tiny building blocks called atoms. Now imagine if this werent the case. This mind-bending concept is at the core of the scientific research that one Florida State University professor -- and hundreds of his colleagues all over the world -- are pursuing.

Recent scientific breakthroughs have shown that most of the matter in the universe -- about four-fifths -- is not made up of atoms, but of something else, called dark matter, said Howard Baer, FSUs J.D. Kimel Professor of Physics. The evidence for dark matter is now overwhelming, and the mandatory amount of dark matter is becoming precisely known.

Baer explained that dark matter is believed to exist in the form of tiny particles that do not interact with light. Because they dont emit or reflect electromagnetic radiation the way atomic, or baryonic, matter does, these dark matter particles havent been directly observed. However, researchers have long theorized their existence based on their gravitational effects on visible matter throughout the universe.

For example, the gravitational effect of dark matter makes galaxies spin faster than one would otherwise expect, Baer said. Also, dark matters gravitational field distorts the light of objects behind it -- creating the so-called lensing effect. By measuring these sorts of phenomena, we can tell that the universe is full of some sort of stuff that we just cant see......... Posted by: Brooke      Read more         Source