Posted on by Fraser Cain

Our Solar System Could Be Special

On the evidence to date, our solar system could be fundamentally different from the majority of planetary systems around stars because it formed in a different way. If that is the case, Earth-like planets will be very rare. After examining the properties of the 100 or so known extrasolar planetary systems and assessing two ways in which planets could form, Dr Martin Beer and Professor Andrew King of the University of Leicester, Dr Mario Livio of the Space Telescope Science Institute and Dr Jim Pringle of the University of Cambridge flag up the distinct possibility that our solar system is special in a paper to be published in the Monthly Notices of the Royal Astronomical Society.

In our solar system, the orbits of all the major planets are quite close to being circular (apart from Pluto’s, which is a special case), and the four giant planets are a considerable distance from the Sun. The extrasolar planets detected so far – all giants similar in nature to Jupiter ? are by comparison much closer to their parent stars, and their orbits are almost all highly elliptical and so very elongated.

“There are two main explanations for these observations,” says Martin Beer. “The most intriguing is that planets can be formed by more than one mechanism and the assumption astronomers have made until now – that all planets formed in basically the same way – is a mistake.”

In the picture of planet formation developed to explain the solar system, giant planets like Jupiter form around rocky cores (like the Earth), which use their gravity to pull in large quantities of gas from their surroundings in the cool outer reaches of a vast disc of material. The rocky cores closer to the parent star cannot acquire gas because it is too hot there and so remain Earth-like.

The most popular alternative theory is that giant planets can form directly through gravitational collapse. In this scenario, rocky cores – potential Earth-like planets – do not form at all. If this theory applies to all the extrasolar planet systems detected so far, then none of them can be expected to contain an Earth-like planet that is habitable by life of the kind we are familiar with.

However, the team are cautious about jumping to a definite conclusion too soon and warn about the second possible explanation for the apparent disparity between the solar system and the known extrasolar systems. Techniques currently in use are not yet capable of detecting a solar-system look-alike around a distant star, so a selection effect might be distorting the statistics – like a fisherman deciding that all fish are larger than 5 inches because that is the size of the holes in his net.

It will be another 5 years or so before astronomers have the observing power to resolve the question of which explanation is correct. Meanwhile, the current data leave open the possibility that the solar system is indeed different from other planetary systems.

Original Source: RAS News Release

Posted on by Fraser Cain

Structure of Saturn’s South Pole

Saturn?s southern polar region exhibits concentric rings of cloud which encircle a dark spot at the pole. To the north, wavy patterns are evident, resulting from the atmosphere moving with different speeds at different latitudes.

The image was taken with the narrow angle camera on July 13, 2004, from a distance of 5 million kilometers (3.1 million miles) from Saturn through a filter sensitive to wavelengths of infrared light centered at 889 nanometers. The image scale is 29 kilometers (18 miles) per pixel. Contrast has been enhanced slightly to aid visibility.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA’s Office of Space Science, Washington, D.C. The imaging team is based at the Space Science Institute, Boulder, Colorado.

For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org.

Posted on by Fraser Cain

Expedition 9 Completes Third Spacewalk

Two International Space Station spacewalkers began rolling out the welcome mat for a new cargo vehicle this morning. Expedition 9 Commander Gennady Padalka and NASA ISS Science Officer Mike Fincke spent 4? hours outside the Station swapping out experiments and installing hardware associated with Europe’s Automated Transfer Vehicle (ATV), scheduled to launch on its maiden voyage to ISS next year.

The ATV is an unpiloted cargo carrier like the Russian Progress supply vehicles, but has a cargo capacity about 2? times that of a Progress. The European Space Agency’s (ESA) ATV is scheduled for its first launch in the fall of 2005 aboard an ESA Ariane 5 rocket from French Guiana. In addition to carrying cargo, including fuel, water, oxygen and nitrogen, it also can reboost the Station. Like the Progress, the ATV will burn up when it re-enters the atmosphere. During the spacewalk Padalka and Fincke worked smoothly around the exterior of the Russian Zvezda Service Module in their Orlan spacesuits. The pair exited the Pirs Docking Compartment airlock at 1:58 a.m. CDT and began work on the Russian segment immediately.

The crewmembers moved to the aft end cone of Zvezda, where they found a wide open workspace. ISS Progress 14 had been undocked from the area on Friday.

Their first task was to replace an experiment, called SKK that exposes materials the space environment with a fresh sample container. They also replaced a Kromka experiment unit that measures contamination from Service Module thruster firings.

Their attention then turned to preparing the Station for the arrival of ATVs by installing new rendezvous and docking equipment. They installed two antennas and replaced three laser reflectors with three more advanced versions than the ones launched with Zvezda in 2000. One three-dimensional reflector was also installed to replace three other old reflectors the spacewalkers removed.

While in the area, the crew also disconnected a cable for a camera that has broken and will be replaced on a future spacewalk. The crew also retrieved another materials experiment, Platan-M. The crew returned to Pirs with the Platan-M, Kromka No.2, SKK No. 2 and the six old laser reflectors in tow.

As they worked at the rear of the Service Module, the three 600-pound Control Moment Gyroscopes that control the orientation in space of the orbiting laboratory approached their saturation level, a condition that had been expected. The Station was placed in free drift while the spacewalkers continued working. Consequently, as power conservation measures were executed, S-band communication was temporarily lost.

At about 4:15 a.m. CDT, the spacewalkers, who were about 40 minutes ahead of their timeline, were asked to clear the area. Once they moved forward, the thrusters on the Service Module were activated to realign the Station’s attitude and S-band communication was also restored.

Subsequently, at about 5 a.m. CDT, the Control Moment Gyroscopes reassumed attitude control and the Service Module thrusters were turned off. The spacewalkers then returned to work at the rear of the Service Module.

The crew closed the hatch and ended the spacewalk at 6:28 a.m. CDT. This was the 55th spacewalk in support of Station assembly and maintenance, the 30th staged from the Station itself, the fifth for Padalka and Fincke’s third.

Information on the crew’s activities aboard the Space Station, future launch dates, as well as Station sighting opportunities from anywhere on the Earth, is available on the Internet at:

http://spaceflight.nasa.gov/

Details on Station science operations can be found on an Internet site administered by the Payload Operations Center at NASA’s Marshall Space Flight Center in Huntsville, Ala., at:

http://scipoc.msfc.nasa.gov/

Original Source: NASA News Release

Posted on by Fraser Cain

New Differences Between Matter and Antimatter

Today, August 2nd 2004, particle physicists from the UK and around the world working on the BABAR experiment at the Stanford Linear Accelerator Center (SLAC) in the USA, announced exciting new results demonstrating a dramatic difference in the behaviour of matter and antimatter. Their discovery may help to explain why the Universe we live in is dominated by matter, rather than containing equal parts matter and anti-matter.

SLAC’s PEP-II accelerator collides electrons and their antimatter counterparts, positrons, to produce an abundance of exotic heavy particle and anti-particle pairs known as B and anti-B mesons. These rare forms of matter and antimatter are short-lived, decaying in turn to other lighter subatomic particles, such as kaons and pions, which can be seen in the BABAR experiment.

“If there were no difference between matter and antimatter, both the B meson and the anti-B meson would exhibit exactly the same pattern of decays. However, our new measurement shows an example of a large difference in decay rates instead.” said Marcello Giorgi, of SLAC, Pisa University and INFN, Spokesman of BABAR.

By sifting through the decays of more than 200 million pairs of B and anti-B mesons, experimenters have discovered striking matter-antimatter asymmetry. “We found 910 examples of the B meson decaying to a kaon and a pion, but only 696 examples for the anti-B”, explained Giorgi. “The new measurement is very much a result of the outstanding performance of SLAC’s PEP-II accelerator and the efficiency of the BABAR detector. The accelerator is now operating at 3 times its design performance and BABAR is able to record about 98% of collisions.”

While BABAR and other experiments have observed matter-antimatter asymmetries before, this is the first time that a difference has been found by simple counting of the number of decays of B and anti-B mesons to the same final state. This effect is known as direct CP violation and is found to be 13%; a similar effect occurs for decays of Kaons and antiKaons but only at the level of 4 parts in a million!

“This is a strong, convincing signal of direct CP violation in B decays, a type of matter-antimatter asymmetry which was expected to exist but has not been observed before. With this discovery the full pattern of matter-antimatter asymmetries is coming together into a coherent picture. I am very excited and pleased as one of my postgraduate students, Carlos Chavez who is currently at SLAC, was directly involved.” said Christos Touramanis of the University of Liverpool.

Dan Bowerman, a member of the BABAR team from Imperial College adds “When the universe began with the big bang, matter and antimatter were created in equal amounts. However, all observations indicate that we live in a universe made only of matter. So we have to ask, what happened to the antimatter? The work at BABAR is bringing us closer to answering this question.”

Subtle differences between the behaviour of matter and antimatter must be responsible for the matter-antimatter imbalance that developed in our universe. But our current knowledge of these differences is incomplete and insufficient to account for the observed matter domination. CP violation is one of the three conditions outlined by Russian physicist Andrei Sakharov to account for the observed imbalance of matter and antimatter in the universe.

Professor Ian Halliday, Chief Executive of the Particle Physics and Astronomy Research Council which funds UK participation in BABAR said: “We still don’t understand fully how the matter dominated Universe we live in has evolved. However this new result, and recent related measurements in BABAR and other experiments around the world, have greatly advanced our understanding in this area. There is still much to discover and learn on this fundamental issue.”

Original Source: PPARC News Release

Posted on by Fraser Cain

MESSENGER Lifts Off for Mercury

NASA’s MESSENGER ? set to become the first spacecraft to orbit the planet Mercury ? launched today at 2:15:56 a.m. EDT aboard a Boeing Delta II rocket from Cape Canaveral Air Force Station, Fla.

The approximately 1.2-ton (1,100-kilogram) spacecraft, designed and built by the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md., was placed into a solar orbit 57 minutes after launch. Once in orbit, MESSENGER automatically deployed its two solar panels and began sending data on its status. Once the mission operations team at APL acquired the spacecraft?s radio signals through tracking stations in Hawaii and California, Project Manager David G. Grant confirmed the craft was operating normally and ready for early system check-outs.

?Congratulations to the MESSENGER launch team for a spectacular start to this mission of exploration to the planet Mercury,? said Orlando Figueroa, Deputy Associate Administrator for Programs in the Science Mission Directorate at NASA Headquarters, Washington. ?While we celebrate this major milestone, let?s keep in mind there is still a lot to do before we reach our destination.?

?All the work that went into designing and building this spacecraft is paying off beautifully,? Grant said. ?Now the team is ready to guide MESSENGER through the inner solar system and put us on target to begin orbiting Mercury in 2011.?

During a 4.9-billion mile (7.9-billion kilometer) journey that includes 15 trips around the sun, MESSENGER will fly past Earth once, Venus twice and Mercury three times before easing into orbit around its target planet. The Earth flyby, in August 2005, and the Venus flybys, in October 2006 and June 2007, will use the pull of the planets’ gravity to guide MESSENGER toward Mercury’s orbit. The Mercury flybys in January 2008, October 2008 and September 2009 help MESSENGER match the planet?s speed and location for an orbit insertion maneuver in March 2011. The flybys also allow the spacecraft to gather data critical to planning a yearlong orbit phase.

Since MESSENGER is only the second spacecraft sent to Mercury ? Mariner 10 flew past it three times in 1974-75 and gathered detailed data on less than half the surface ? the mission has an ambitious science plan. With a package of seven science instruments MESSENGER will determine Mercury’s composition; image its surface globally and in color; map its magnetic field and measure the properties of its core; explore the mysterious polar deposits to learn whether ice lurks in permanently shadowed regions; and characterize Mercury’s tenuous atmosphere and Earth-like magnetosphere.

?It took technology more than 30 years, from Mariner 10 to MESSENGER, to bring us to the brink of discovering what Mercury is all about,? said Dr. Sean C. Solomon, MESSENGER?s principal investigator from the Carnegie Institution of Washington, who leads a science team of investigators from 13 institutions across the U.S. ?By the time this mission is done we will see Mercury as a much different planet than we think of it today.?

MESSENGER, short for MErcury Surface, Space ENvironment, Geochemistry, and Ranging, is the seventh mission in NASA’s Discovery Program of lower cost, scientifically focused exploration projects. APL manages the mission for NASA?s Office of Space Science, built the spacecraft and will operate MESSENGER during flight. MESSENGER is the 61st spacecraft built at APL.

?With MESSENGER on its way to Mercury, the reality is sinking in that in a few years, we will see things that no human has ever seen and know infinitely more about the formation of the solar system than we know today,? said Dr. Michael D. Griffin, head of the APL Space Department.

The countdown and launch was managed by the NASA Launch Services Program based at the John F. Kennedy Space Center, Fla. The Delta II launch service was provided by Boeing Expendable Launch Systems, Huntington Beach, Calif. MESSENGER’s science instruments were built by APL; NASA Goddard Space Flight Center, Greenbelt, Md.; University of Michigan, Ann Arbor; and University of Colorado, Boulder. GenCorp Aerojet, Sacramento, Calif., and Composite Optics Inc., San Diego, provided MESSENGER’s propulsion system and composite structure, respectively. KinetX, Inc., Simi Valley, Calif., leads the navigation team. NASA’s Jet Propulsion Laboratory, Pasadena, Calif., manages the Deep Space Network of antenna stations the team uses to communicate with MESSENGER.

For photos of the launch or more information about the MESSENGER mission visit,

http://messenger.jhuapl.edu or http://www.ksc.nasa.gov

Original Source: NASA News Release

Posted on by Fraser Cain

Lagoon Nebula By Hubble

This NASA/ESA Hubble Space Telescope image reveals a pair of half a light-year long interstellar ‘twisters’, eerie twisted funnel structures, in the heart of the Lagoon Nebula (M8).

The central hot star, O Herschel 36 (shown here on left, red), is the primary source of the ionising radiation for the brightest region in the nebula, called the ‘Hourglass’. Other hot stars, also present in the nebula, are ionising the outer visible parts of the nebulous material.

This ionising radiation heats up and ‘evaporates’ the surfaces of the clouds (seen as a blue ‘mist’ at the right of the image), and drives violent stellar winds which tear into the cool clouds.

Analogous to the phenomena of tornadoes on Earth, the large difference in temperature between the hot surface and cold interior of the clouds, combined with the pressure of starlight, may produce strong horizontal ‘windshear’ to twist the clouds into their tornado-like appearance.

The Lagoon Nebula and nebulae in other galaxies are sites where new stars are being born from dusty molecular clouds. These regions are the ‘space laboratories’ for astronomers to study how stars form and the interactions between the winds from stars and the gas nearby. By studying the wealth of data revealed by Hubble, astronomers will understand better how stars form in the nebulae.

These colour-coded images are the combination of individual exposures taken in 1995 with Hubble’s Wide Field and Planetary Camera 2 (WFPC2).

Original Source: ESA News Release

Posted on by Fraser Cain

New Perspective on Melas Chasma

This image of the southern part of Valles Marineris, called Melas Chasma, was obtained by the High Resolution Stereo Camera (HRSC) on board the ESA Mars Express spacecraft.

This image was taken at a resolution of approximately 30 metres per pixel. The displayed region is located at the southern rim of the Melas Chasma, centred at Mars latitude 11? S and Mars longitude 286? E. The images were taken on orbit 360 of Mars Express.

This perspective view has been turned in such a way that the observer has a view of the southern scarp, almost 5000 metres high. The basin on the floor of the valley is on the opposite side, bordered by a ridge.

On its flanks it is possible to make out some layering. However, the nature of the bright material, possibly some kind of deposit, is still unknown.

This perspective view was created by using the nadir (vertical view) channel and one stereo channel of the HRSC to produce a digital model of the terrain. Please note that image resolution has been reduced for use on the internet.

Original Source: ESA News Release

Posted on by Fraser Cain

Icy Tethys

Image credit: NASA/JPL/SSI
This view of icy Tethys (1060 kilometers, 659 miles across) shows a large crater in the moon?s southern hemisphere with a central peak. Other surface details of this heavily cratered surface are faintly visible. Cassini was at the time speeding away from the Saturn system on its initial long, looping orbit.

The image was taken in visible light with the narrow angle camera on July 13, 2004, from a distance of about 4.8 million kilometers (3 million miles) from Tethys and at a Sun-Tethys-spacecraft, or phase, angle of 97 degrees. The image scale is 29 kilometers (18 miles) per pixel. The image has been magnified by a factor of two to aid visibility.

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini-Huygens mission for NASA’s Office of Space Science, Washington, D.C. The imaging team is based at the Space Science Institute, Boulder, Colorado.

For more information about the Cassini-Huygens mission, visit http://saturn.jpl.nasa.gov and the Cassini imaging team home page, http://ciclops.org.

Original Source: CICLOPS

Posted on by Fraser Cain

Search for Origins Programs Shortlisted

NASA has selected nine studies to investigate new ideas for future mission concepts within its Astronomical Search for Origins Program.

Among the new mission ideas are some that will survey one billion stars within our own galaxy, measure the distribution of galaxies in the distant universe, study dust and gas between galaxies, study organic compounds in space and investigate their role in planetary system formation, and create an optical-ultraviolet telescope to replace the Hubble Space Telescope (HST).

The products from these concept studies will be used for future planning of missions complementing the existing suite of operating missions, including the Hubble and Spitzer Space Telescopes, and developmental missions such as the James Webb Space Telescope and Terrestrial Planet Finder.

Each of the selected studies will have eight months to further develop and refine concepts for missions addressing different aspects of Origins Program science. The Origins Program seeks to address the fundamental questions: “How did we get here?” and “Are we alone?” NASA received 26 proposals in response to this call for mission concepts.

The selected proposals and their principal investigators are:

– BLISS: Revealing the Nature of the Far-IR Universe, Matt Bradford, Jet Propulsion Laboratory, Pasadena, Calif. BLISS will enable far-infrared spectroscopy of the galaxies that make up the far-infrared background out to distances of some of the farthest galaxies known today. BLISS spectral surveys will chart the history of creation of elements heavier than helium and energy production through cosmic time.

– Origins Billion Star Survey (OBSS), Kenneth Johnston, U.S. Naval Observatory, Washington. OBSS will provide a complete census of giant extrasolar planets for all types of stars in our galaxy and the demographics of stars within 30,000 light-years of the sun.

– The Space Infrared Interferometric Telescope (SPIRIT), David Leisawitz, Goddard Space Flight Center, Greenbelt, Md. SPIRIT is an imaging and spectral Michelson interferometer operating in the mid- to far-infrared region of the spectrum. Its very high angular resolution in the far infrared will enable revolutionary developments in the field of star and planet formation research.

– Cosmic Inflation Probe (CIP), Gary Melnick, Smithsonian Astrophysical Observatory, Cambridge, Mass. CIP will measure the shape of cosmic inflation potential by conducting a space-based near-infrared large-area redshift survey capable of detecting galaxies that formed early in the history of the universe.

– HORUS: High ORbit Ultraviolet-visible Satellite, Jon Morse, Arizona State University, Tempe. HORUS will conduct a step-wise, systematic investigation of star formation in the Milky Way, nearby galaxies and the high-redshift universe; the origin of the elements and cosmic structure; and the composition of and physical conditions in the extended atmospheres of extrasolar planets.

– Hubble Origins Probe, Colin Norman, Johns Hopkins University, Baltimore. This mission seeks to combine instruments built for the fifth HST servicing mission: Cosmic Origins Spectrograph and Wide Field Camera 3. This new space telescope at the forefront of modern astronomy will have a unifying focus on the period when the great majority of star and planet formation, heavy element production, black-hole growth and galaxy assembly took place.

– The Astrobiology SPace InfraRed Explorer (ASPIRE) Mission: A Concept Mission to Understand the Role Cosmic Organics Play in the Origin of Life, Scott Sandford, Ames Research Center, Moffett Field, Calif. ASPIRE is an mid- and far-infrared infrared space observatory optimized to spectroscopically detect and identify organic compounds and related materials in space, and understand how these materials are formed, evolve and find their way to planetary surfaces.

– The Baryonic Structure Probe, Kenneth Sembach, Space Telescope Science Institute, Baltimore. The Baryonic Structure Probe will strengthen the foundations of observational cosmology by directly detecting, mapping and characterizing the cosmic web of matter in the early universe, its inflow into galaxies, and its enrichment with elements heavier than hydrogen and helium (the products of stellar and galactic evolution).

– Galaxy Evolution and Origins Probe (GEOP), Rodger Thompson, University of Arizona. GEOP observes more than five million galaxies to study the mass assembly of galaxies, the global history of star formation, and the change of galaxy size and brightness over a volume of the universe large enough to determine the fluctuations of these processes.

More information on NASA’s Origins Program is available on the Internet at:

http://origins.jpl.nasa.gov/

Original Source: NASA News Release

Posted on by Fraser Cain

Public Invited to Help Catalog Mars

NASA scientists have modified a scientific Web site so the general public can inspect big regions and smaller details of Mars’ surface, a planet whose alien terrain is about the same area as Earth’s continents.

After adding ‘computer tools’ to the ‘Marsoweb’ Internet site, NASA scientists plan to ask volunteers from the public to virtually survey the vast red planet to look for important geologic features hidden in thousands of images of the surface. The Web site is located at:

http://marsoweb.nas.nasa.gov/landingsites/index.html

“The initial reason to create Marsoweb was to help scientists select potential Mars landing sites for the current Mars Exploration Rover (MER) mission,” according to Virginia Gulick, a scientist from the SETI Institute, Mountain View, Calif., who works at NASA Ames Research Center, located in California’s Silicon Valley. “The Web site was designed just for Mars scientists so they could view Mars data easily,” she added.

But when the first Mars Exploration Rover landed on Mars in January, the general public discovered Marsoweb. More than a half million ‘unique visitors’ found the page, and the Web experienced about 26.7 million ‘hits’ in January.

“An interactive data map on Marsoweb allows users to view most Mars data including images, thermal inertia, geologic and topographical maps and engineering data that includes rock abundance,” Gulick said. Thermal inertia is a material’s capacity to store heat (usually in daytime) and conduct heat (often at night). “The engineering data give scientists an idea of how smooth or rocky the local surface is,” Gulick explained.

To examine a large number of distinctive or interesting geologic features on the red planet close up would take an army of people because Mars’ land surface is so big. Such a multitude of explorers – modern equivalents of America’s early pioneers – may well survey details of Mars through personal computers.

Researchers hope that volunteers will help with an upcoming Mars imaging experiment. NASA scientists are getting ready for the High Resolution Imaging Science Experiment (HiRISE) that will fly on the Mars Reconnaissance Orbiter (MRO) mission, slated for launch in August 2005. Gulick, co-investigator and education and public outreach lead of the HiRISE team, said that the experiment’s super high-resolution camera will be able to capture images of objects on Mars’ surface measuring about a yard (one meter) wide.

User-friendly ‘Web tools’ soon will be available to the science community and the public to view and analyze HiRISE images beginning in November 2006 and to submit image observation requests, according to HiRISE scientists. If all goes according to plan, a request form will be on the Internet for use by scientists and the public about the time of the Mars Reconnaissance Orbiter launch in 2005. Marsoweb computer scientist Glenn Deardorff, Gulick and other HiRISE team members are now designing Web-friendly software ‘tools’ to allow the public to examine and evaluate HiRISE images.

“We will ask volunteers to help us create ‘geologic feature’ databases of boulders, gullies, craters – any kind of geologic feature that may be of interest,” Gulick explained. “Scientists or students can use these data bases to propose theories about Mars that could be proven by future exploration.”

Preliminary details about Mars Reconnaissance Orbiter HiRISE’s exploration of Mars are on the World Wide Web at:

http://marsoweb.nas.nasa.gov/hirise/

The current Marsoweb site includes animated ‘fly-throughs’ of some Mars locations. The site also permits users to fine-tune Mars images for brightness, contrast and sharpness as well as make other adjustments.

NASA’s Jet Propulsion Laboratory, operated by the California Institute of Technology in Pasadena, Calif., manages the Mars Exploration Rover and Mars Reconnaissance Orbiter missions for the NASA Office of Space Science, Washington, D.C.

Original Source: NASA News Release