Dark energy: it's weak, it's everywhere, and it's pulling the universe apart. But no one knows what dark energy is.

February 22, 2005

Although the universe we live in is full of mysteries that challenge today's brightest physicists and astronomers, no entity is quite as baffling as the so-called dark energy that makes up the bulk of the cosmos.

"It's most of the universe, and we don't have a clue what it is," astronomer Adam Riess said on Friday following a news briefing at the American Association for the Advancement of Science meeting in Washington, D.C.

Dark energy appears to be a kind of anti-gravity force that pushes galaxies apart. It's estimated to account for some two-thirds of the energy content of the universe — and yet, physicists struggle to explain what causes it.and why it has the particular strength it does.
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Using the X-ray Satellite XMM-Newton researchers measure velocities near the speed of light in the vicinity of cosmic mass monsters.

23 Feb 2005

European astronomers succeeded for the first time to confirm the signatures predicted near black holes by Albert Einstein's theory of Relativity in the light of the cosmic X-ray background. The group of scientists led by Günther Hasinger, director at the Max-Planck-Institute for extraterrestrial Physics in Garching near Munich, could identify the spectral fingerprint of iron atoms. They observed a strong, relativistically smeared iron line in the average spectrum of roughly 100 active galaxies, whose X-ray light had been emitted when the Universe was less than half of its current age.
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Very Large Telescope Finds Planet-Sized Transiting Star.

3 March 2005

An international team of astronomers have accurately determined the radius and mass of the smallest core-burning star known until now.

The observations were performed in March 2004 with the FLAMES multi-fibre spectrograph on the 8.2-m VLT Kueyen telescope at the ESO Paranal Observatory (Chile). They are part of a large programme aimed at measuring accurate radial velocities for sixty stars for which a temporary brightness "dip" has been detected during the OGLE survey.

The astronomers find that the dip seen in the light curve of the star known as OGLE-TR-122 is caused by a very small stellar companion, eclipsing this solar-like star once every 7.3 days.

This companion is 96 times heavier than planet Jupiter but only 16% larger. It is the first time that direct observations demonstrate that stars less massive than 1/10th of the solar mass are of nearly the same size as giant planets. This fact will obviously have to be taken into account during the current search for transiting exoplanets.

In addition, the observations with the Very Large Telescope have led to the discovery of seven new eclipsing binaries, that harbour stars with masses below one-third the mass of the Sun, a real bonanza for the astronomers.
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[url=http://www.spitzer.caltech.edu/Media/releases/ssc2005-08/release.shtml]NASA's Spitzer Space Telescope Exposes Dusty Galactic Hideouts<a>

March 1, 2005

How do you hide something as big and bright as a galaxy? You smother it in cosmic dust. NASA's Spitzer Space Telescope saw through such dust to uncover a hidden population of monstrously bright galaxies approximately 11 billion light-years away.

These strange galaxies are among the most luminous in the universe, shining with the equivalent light of 10 trillion suns. But, they are so far away and so drenched in dust, it took Spitzer's highly sensitive infrared eyes to find them.

"We are seeing galaxies that are essentially invisible," said Dr. Dan Weedman of Cornell University, Ithaca, N.Y., co-author of the study detailing the discovery, published in today's issue of the Astrophysical Journal Letters. "Past infrared missions hinted at the presence of similarly dusty galaxies over 20 years ago, but those galaxies were closer. We had to wait for Spitzer to peer far enough into the distant universe to find these."
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ESO-VLT and ESA XMM-Newton Together Discover Earliest Massive Cluster of Galaxies Known

2 March 2005

Combining observations with ESO's Very Large Telescope and ESA's XMM-Newton X-ray observatory, astronomers have discovered the most distant, very massive structure in the Universe known so far.

It is a remote cluster of galaxies that is found to weigh as much as several thousand galaxies like our own Milky Way and is located no less than 9,000 million light-years away.

The VLT images reveal that it contains reddish and elliptical, i.e. old, galaxies. Interestingly, the cluster itself appears to be in a very advanced state of development. It must therefore have formed when the Universe was less than one third of its present age.

The discovery of such a complex and mature structure so early in the history of the Universe is highly surprising. Indeed, until recently it would even have been deemed impossible.
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Astronomers Detect Powerful Bursting Radio Source
Discovery Points to New Class of Astronomical Objects

March 2, 2005

Astronomers at Sweet Briar College and the Naval Research Laboratory (NRL) have detected a powerful new bursting radio source whose unique properties suggest the discovery of a new class of astronomical objects. The researchers have monitored the center of the Milky Way Galaxy for several years and reveal their findings in the March 3, 2005 edition of the journal, “Nature”.

Principal investigator, Dr. Scott Hyman, professor of physics at Sweet Briar College, said the discovery came after analyzing some additional observations from 2002 provided by researchers at Northwestern University. “"We hit the jackpot!” Hyman said referring to the observations. “An image of the Galactic center, made by collecting radio waves of about 1-meter in wavelength, revealed multiple bursts from the source during a seven-hour period from Sept. 30 to Oct. 1, 2002 — five bursts in fact, and repeating at remarkably constant intervals.”
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March 9, 2005

Cassini Images of Titan Reveal an Active, Earth-like World
Saturn's largest and hazy moon, Titan, has a surface shaped largely by Earth-like processes of tectonics, erosion, winds, and perhaps volcanism. The findings are published in this week's issue of the journal Nature. Titan, long held to be a frozen analog of early Earth, has liquid methane on its cold surface, unlike the water found on our home planet. Among the new discoveries is what may be a long river, roughly 1,500 kilometers long (930 miles). Scientists have also concluded that winds on Titan blow a lot faster than the moon rotates, a fact long predicted but never confirmed until now...

Astronomers discover a planet-sized star

March 11, 2005

PLANET QUEST -- An international team of astronomers searching for new planets has discovered something unexpected - a star only slightly larger than the planet Jupiter.

The new star, part of a binary system, was discovered using the "transit" method, which measures the slight dip in a star's brightness that occurs when a smaller object passes in front of it. The tiny star, named OGLE-TR-122, decreases the light reaching the Earth from its larger companion by 1.5 percent during each orbit.

Astronomers said the future planet searches that use the "transit" method will have to be careful to distinguish between stellar imposters such as OGLE-TR-122 and true planets.

The new star is 96 times heavier than planet Jupiter, but only 16% larger. Furthermore, it is smaller than many of the 146 extrasolar planets that have been discovered thus far.

The recent observations also detected seven other small stars with masses below one-third the mass of the Sun, indicating that such stars are not rare, according to a European Southern Observatory (ESO).

The observations were carried out using the ESO's Very Large Telescope in Chile.

Read the full release here

Black holes influence knowledge of the universe.

Thursday, March 10, 2005


Black holes have a reputation for voraciously eating everything in their immediate neighborhood, but these large gravity wells also affect electromagnetic radiation and may hinder our ability to ever locate the center of the universe, according to an international research team.

"Any attempt to discover what was happening a long time ago at the beginning of our universe must take into account what gravitationally assisted negative refraction does to the radiation being viewed," says Dr. Akhlesh Lakhtakia, distinguished professor of engineering science and mechanics, Penn State.
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Young Universe Looks Like "Vegetable Soup"

Wednesday, March 9, 2005

What did the universe look like when it was only 2 to 3 billion years old? Astronomers used to think it was a pretty simple place containing relatively small, young star-forming galaxies. Researchers now are realizing that the truth is not that simple. Even the early universe was a wildly complex place. Studying the universe at this early stage is important in understanding how the galaxies near us were assembled over time.

Jiasheng Huang (Harvard-Smithsonian Center for Astrophysics) said, "It looks like vegetable soup! We're detecting galaxies we never expected to find, having a wide range of properties we never expected to see."
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Interactive Feature: Spitzer Eyes the Infrared Universe

The magic of NASA's Spitzer Space Telescope comes alive in an online interactive presentation. The show-and-tell feature highlights colorful images of galaxies, nebulas and other celestial wonders, all captured during the mission's first year-and-a-half in space. (Mar. 11)

btw a nice Flash Animation

Greetings from Germany NRW
Ulli S@h Berkeley's Staff Friends Club m7 ©

Cassini Finds an Atmosphere on Saturn's Moon Enceladus

March 16, 2005

The Cassini spacecraft's two close flybys of Saturn's icy moon Enceladus have revealed that the moon has a significant atmosphere. Scientists, using Cassini's magnetometer instrument for their studies, say the source may be volcanism, geysers, or gases escaping from the surface or the interior.

When Cassini had its first encounter with Enceladus on Feb. 17 at an altitude of 1,167 kilometers (725 miles), the magnetometer instrument saw a striking signature in the magnetic field. On March 9, Cassini approached to within 500 kilometers (310 miles) of Enceladus' surface and obtained additional evidence.

The observations showed a bending of the magnetic field, with the magnetospheric plasma being slowed and deflected by the moon. In addition, magnetic field oscillations were observed. These are caused when electrically charged (or ionized) molecules interact with the magnetic field by spiraling around the field line. This interaction creates characteristic oscillations in the magnetic field at frequencies that can be used to identify the molecule. The observations from the Enceladus flybys are believed to be due to ionized water vapor.

"These new results from Cassini may be the first evidence of gases originating either from the surface or possibly from the interior of Enceladus," said Dr. Michele Dougherty, principal investigator for the Cassini magnetometer and professor at Imperial College in London. In 1981, NASA's Voyager spacecraft flew by Enceladus at a distance of 90,000 kilometers (56,000 miles) without detecting an atmosphere. It's possible detection was beyond Voyager's capabilities, or something may have changed since that flyby.

This is the first time since Cassini arrived in orbit around Saturn last summer that an atmosphere has been detected around a moon of Saturn, other than its largest moon, Titan. Enceladus is a relatively small moon. The amount of gravity it exerts is not enough to hold an atmosphere very long. Therefore, at Enceladus, a strong continuous source is required to maintain the atmosphere.

The need for such a strong source leads scientists to consider eruptions, such as volcanoes and geysers. If such eruptions are present, Enceladus would join two other such active moons, Io at Jupiter and Triton at Neptune. "Enceladus could be Saturn's more benign counterpart to Jupiter's dramatic Io," said Dr. Fritz Neubauer, co-investigator for the Cassini magnetometer, and a professor at the University of Cologne in Germany.

Since the Voyager flyby, scientists have suspected that this moon is geologically active and is the source of Saturn's icy E ring. Enceladus is the most reflective object in the solar system, reflecting about 90 percent of the sunlight that hits it. If Enceladus does have ice volcanoes, the high reflectivity of the moon's surface might result from continuous deposition of icy particles originating from the volcanoes.

Enceladus' diameter is about 500 kilometers (310 miles), which would fit in the state of Arizona. Yet despite its small size, Enceladus exhibits one of the most interesting surfaces of all the icy satellites.

For images and information on the Cassini mission visit http://saturn.jpl.nasa.gov and http://www.nasa.gov/cassini

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 Science Mission Directorate, Washington, D.C. The Cassini orbiter was designed, developed and assembled at JPL.

Diagnostic Tests Planned for Instrument on Mars Rover

March 16, 2005

NASA has suspended use of one of the mineral-identifying tools on the Opportunity Mars rover while experts troubleshoot a problem with getting data from the instrument, the robot's miniature thermal emission spectrometer.

"As always, our first priority is to protect the instrument, so we have turned it off while we plan diagnostic tests," said Jim Erickson of NASA's Jet Propulsion Laboratory, Pasadena, Calif., project manager for the Mars Exploration Rover Project. "Opportunity's other instruments are healthy and providing excellent science, and Spirit's entire instrument suite is working well and being kept busy by the science team."

Both Opportunity and Spirit, its twin, have been examining Mars since January 2004, more than four times as long as their successful three-month primary missions. While researchers work to diagnose the spectrometer-data problem and seek the best way to mend it or work around it, Opportunity is continuing its journey and observing a crater called "Vostok." On the other side of the planet, meanwhile, martian winds have revealed themselves as dust devils in new images from Spirit and caused mixed effects on the rover itself, depositing dust on a camera and removing dust from solar panels.

On March 3 and 4, Opportunity transmitted data sets for 17 successful readings by its miniature thermal emission spectrometer but also reported that eight other attempted readings yielded incomplete data sets. This spectrometer, from high on the rover's mast, observes rocks and other targets from afar. It measures the infrared radiation they emit in 167 different wavelengths, providing information about the targets' composition. Two other types of spectrometers, mounted on the rover's robotic arm, provide additional information about composition when the rover is close enough to touch the target.

Researchers are considering several possible root causes for the spectrometer-data problem. One possibility is malfunctioning of an optical switch that tells a mirror in the instrument when to begin moving. Another is that the mirror is not properly moving at a constant velocity. "If it is the optical switch, we could use a redundant one built into the instrument," said Dr. Phil Christensen of Arizona State University, Tempe, lead scientist for the miniature thermal emission spectrometers on both rovers. He added that, if the root cause cannot be remedied, scientists could still get useful data from the instrument in its currently impaired condition.

Even a total loss of the miniature thermal emission spectrometer would not end the rover's usefulness. In fact, NASA took a calculated risk by disabling this instrument on Opportunity 10 months ago, though the current problem appears unrelated to potential damage anticipated then. At that time, rover operators began using a "deep sleep" technique to conserve energy on Opportunity during reduced-sunshine months of Mars' winter. Turning off power to overnight heaters let the instrument get cold enough to possibly damage its beam-splitter. However, the spectrometer kept working through the coldest months. Christensen said, "What we're seeing now does not appear to be any problem with the beam-splitter."

The rover team is not restricting use of Spirit's miniature thermal emission spectrometer while troubleshooting the problem on Opportunity.

Spirit's work capabilities grew with a sudden jump in output from solar panels on March 9, which caused the daily power supply to double. In a possibly related development three days earlier, some dust appeared to have blown onto lenses of Spirit's front hazard-avoidance camera, enough for slight mottling in images from both the left and right eyes of the stereo camera, but not enough to affect the usefulness of the camera. Mottling in left-eye images cleared markedly the same day the power increased. Team members speculated that Spirit's power boost, like similar ones on Opportunity in October, resulted from wind removing some accumulated dust from solar panels. Spirit captured pictures of dust-lofting whirlwinds on March 10, adding evidence for windy local conditions. Images the next day showed solar panels cleaned of most of their dust buildup.

Opportunity's rear hazard-avoidance camera picked up some dust contamination three months ago. The dust on it has not affected operations and has neither decreased nor increased perceptibly since first noticed. No dust has contaminated lenses of the navigation cameras or panoramic cameras on either rover. From all cameras combined, the rovers have returned more than 72,000 images. Images and other geological data from Spirit and Opportunity are successfully providing unprecedented evidence about wet environmental conditions in Mars' past.

JPL, a division of the California Institute of Technology in Pasadena, has managed NASA's Mars Exploration Rover project since it began in 2000. Images and additional information about the rovers and their discoveries are available on the Internet at http://www.nasa.gov/vision/universe/solarsystem/mer_main.html and http://marsrovers.jpl.nasa.gov

Scientist hails 'exciting step' toward seeing extrasolar planets

March 22, 2005

(PLANETQUEST) -- NASA's long-range goal of finding Earthlike planets around other stars was brought a step closer to reality with the direct capture of light from two extrasolar planets, a prominent extrasolar planet researcher said this week.

"In the past we've just talked about directly detecting extrasolar planets; now we've started to do it," said Dr. Charles Beichman, executive director of the Michelson Science Center.

Although the method used by Spitzer can't be extended down to Earth-size planets, it represents an important step toward that ultimate goal, Beichman said.

"In the end, most of the information we learn about planets will be from seeing their photons [particles of light]. This is the very first step toward eventually being able to see Earthlike planets, and it's an exciting one," he said.

Over the past decade, more than 140 extrasolar planets have been discovered through indirect evidence. In new studies, announced Wednesday, NASA's Spitzer Space Telescope for the first time directly observed the warm infrared glows of two of those planets. (Full story)

"The actual job of detecting Earths is a factor of 1,000 times more difficult than seeing gas giants," Beichman said. "But the very fact that we're able to detect photons from large planets confirms we can directly see planets. A voyage of 1,000 miles starts with the first step, and this is the first step."

NASA has planned a series of future space telescopes that will dramatically extend current capabilities of observing extrasolar planets, including:

- The Kepler Mission, scheduled for launch in 2008, which will determine the prevalence of Earth-size planets in our Milky Way Galaxy;
- SIM PlanetQuest, scheduled for launch in 2011, which will detect planets nearly as small as Earth;
- Terrestrial Planet Finder, which will directly observe planets as small as Earth and search for the signatures of life.

The Michelson Science Center is a science operations and analysis service organization operated by the California Institute of Technology in coordination with the Jet Propulsion Laboratory.

ESO's Telescopes Uncover Super Star Cluster in the Milky Way

22 March 2005

Super star clusters are groups of hundreds of thousands of very young stars packed into an unbelievably small volume. They represent the most extreme environments in which stars and planets can form.

Until now, super star clusters were only known to exist very far away, mostly in pairs or groups of interacting galaxies. Now, however, a team of European astronomers [1] have used ESO's telescopes to uncover such a monster object within our own Galaxy, the Milky Way, almost, but not quite, in our own backyard!

The newly found massive structure is hidden behind a large cloud of dust and gas and this is why it took so long to unveil its true nature. It is known as "Westerlund 1" and is a thousand times closer than any other super star cluster known so far. It is close enough that astronomers may now probe its structure in some detail.
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Unveiling the high energy Milky Way reveals 'dark accelerators'

24 March 2005

In the March 25th 2005 issue of Science Magazine, the High Energy Stereoscopic System (H.E.S.S.) team of international astrophysicists, including UK astronomers from the University of Durham, report results of a first sensitive survey of the central part of our galaxy in very high energy (VHE) gamma-rays. Included among the new objects discovered are two 'dark accelerators' - mysterious objects that are emitting energetic particles, yet apparently have no optical or x-ray counterpart.
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NASA 'Ambassadors' Spread the Scientific Word

March 24, 2005

Space enthusiasts have joined together for an eighth year as part of NASA's Solar System Ambassadors Program, a volunteer- based group whose mission is to educate the public about the wonders of space exploration.

Ambassadors are everyday citizens with an interest in space science and the solar system. With 459 ambassadors coming from all 50 states and Puerto Rico, the program has a wide variety.

"The diversity in this year's applicants is particularly striking," said Kay Ferrari, coordinator of the program at NASA's Jet Propulsion Laboratory in Pasadena, Calif. "While the Solar System Ambassador program has long been the haven for space enthusiasts from all walks of life, it is particularly inspiring to see the range of fields represented: firefighter, high school senior, retired Wall Street analyst, Navy medic and attorney."

The Solar System Ambassador program was created in 1997. The ambassadors' main objective is to spread knowledge of the solar system by organizing community events and visiting schools.

To prepare, ambassadors participate in a series of online training courses provided by JPL. Educational materials are supplied by the space missions.

Ambassador Susan Cabello of Laredo Texas, a mother of two boys, has a special interest in educating the young and a passion for space.

"I want to reach all children," said Cabello, who has an associate's degree in criminology and plans to hold her next event for Earth-Sun Day at Laredo Community College. "Middle school is a place to attempt to reach children first. I believe that if you can give kids at that age a dream to work for, they can achieve it. I also want to visit high schools and tell kids to study the tough classes for their career and personal satisfaction."

Navy medic Oteasha Leonard, who is stationed in San Diego, has similar aspirations. Her first event is the Military Kids Space Day in San Diego.

"No child should be left out when it comes to education," said Leonard, who once attended a school for Aerospace Medicine Technology. "Maybe one of the children I reach out to will become an astronaut, astronomer or scientist. I want to give them a head start at the opportunity."

Lisa Olsen, a developmental training supervisor from Amboy, Ill., says space captured her attention at a young age, and she now has the ability to put that interest to good use.

"I would like to reach the people who have always had an interest in astronomy and space exploration, but have been too busy, insecure, or just have not had the opportunity to explore the amazing events. I would also hope to get more people, women in particular, excited about the field of science and technology."

For more information on JPL's Solar System Ambassador program, visit http://www.jpl.nasa.gov/ambassador/front.html or contact Kay Ferrari at ambassadors@jpl.nasa.gov or (818) 354-7581. A calendar of events hosted by ambassadors is available at http://www2.jpl.nasa.gov/ambassador/events.html

JPL is managed for NASA by the California Institute of Technology in Pasadena, Calif.

March 25, 2005

NASA's Terra satellite, circling the globe for five years, keeps a watchful eye on Earth's "vital signs" and has documented Earth's changing landmasses, surface temperature, oceans, clouds and atmosphere. Five onboard instruments collect data and also snap some spectacular sights. A new interactive tour highlights some of the spectacular sights the mission snaps as it helps scientists track changes to our home planet.

Terra's World Tour - interactive Flash feature

NASA offers cash for new space ideas

WASHINGTON – In an effort to stimulate fresh thinking, the National Aeronautics and Space Administration has announced that it will offer cash prizes for innovative technology that can be applied to space exploration.

The competitions, open to large and small companies, colleges, technology groups and individuals, are seen as ways to promote innovation by letting contestants pose any solution that works to solve a problem, an agency official said Friday.

The prizes are a new approach for NASA in its effort to find new space technology.

The program, part of President Bush's new vision of exploration for the space agency, was inspired in part by last year's Ansari X Prize of $10 million for the first private piloted suborbital flights and in part by the incentive programs that have long been sponsored by the Pentagon's Defense Advanced Research Projects Agency.

Prizes will range from $1,000 to $10,000.

New York Times News Service