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Old 25.07.2004, 21:53   #1
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New martian meteorite found in Antarctica

Thursday, July 22, 2004 Posted: 10:04 AM EDT (1404 GMT)

WASHINGTON (Reuters) -- A meteorite from Mars has been discovered in Antarctica, one of only about 30 known martian space rocks on Earth.


Antartica's frozen expanse holds many well-preserved meteorites.

"We've gotten something like 13,000 meteorites from Antarctica and this is only the sixth one from Mars," Timothy McCoy, curator of meteorites at the Smithsonian Institution, said by telephone on Wednesday.

The rest of the known martian meteorites on this planet were found outside Antarctica, McCoy said by telephone.

What makes this rock special is its comparatively large size, he said: "It's a 700 gram rock (about 1.5 pounds) but by meteorite standards it's a mountain of material."

Scientists can do effective work on amounts as little as one-thousandth of a gram, McCoy said.

At this point, there is no suggestion that the new meteorite -- discovered December 15, 2003, on an ice field some 466 miles (750 km) from the South Pole -- bears any evidence of possible microscopic fossilized life.

Some scientists believe an earlier meteorite found in Antarctica and publicly unveiled in 1996 bore such signs; it is still being investigated.

The new martian meteorite was found as part of a cooperative effort funded by NASA and supported by the National Science Foundation.

Smithsonian scientists said they can establish the origin of the martian meteorites by their mineralogy, texture and oxidized nature.

http://www.cnn.com/2004/TECH/space/07/22/space.meteorite.reut/index.html
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Old 25.07.2004, 22:06   #2
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I wonder how do they distinguish between martian objects and others. This could have be any object from our galaxy. I don't believe they are looking for the corresponding missing part on Mars surface
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Old 29.07.2004, 18:28   #3
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Quote:
Originally Posted by acid
I wonder how do they distinguish between martian objects and others. This could have be any object from our galaxy. I don't believe they are looking for the corresponding missing part on Mars surface
Perhaps by maintainance of Fe2O3
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Old 30.07.2004, 04:48   #4
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Quote:
Originally Posted by acid
I wonder how do they distinguish between martian objects and others. This could have be any object from our galaxy. I don't believe they are looking for the corresponding missing part on Mars surface
Spectroscopy is a great science.
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Old 30.07.2004, 05:08   #5
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Cassini



Encircled in purple stratospheric haze, Titan appears as a softly glowing sphere in this colorized image taken one day after Cassini's first flyby of that moon.

This image shows two thin haze layers. The outer haze layer is detached and appears to float high in the atmosphere. Because of its thinness, the high haze layer is best seen at the moon's limb.

The image was taken using a spectral filter sensitive to wavelengths of ultraviolet light centered at 338 nanometers. The image has been falsely colored: The globe of Titan retains the pale orange hue our eyes usually see, and both the main atmospheric haze and the thin detached layer have been brightened and given a purple color to enhance their visibility.

The best possible observations of the detached layer are made in ultraviolet light because the small haze particles which populate this part of Titan's upper atmosphere scatter short wavelengths more efficiently than longer visible or infrared wavelengths.

Images like this one reveal some of the key steps in the formation and evolution of Titan's haze. The process is thought to begin in the high atmosphere, at altitudes above 400 kilometers (250 miles), where ultraviolet light breaks down methane and nitrogen molecules. The products are believed to react to form more complex organic molecules containing carbon, hydrogen and nitrogen that can combine to form the very small particles seen as haze. The bottom of the detached haze layer is a few hundred kilometers above the surface and is about 120 kilometers (75 miles) thick.

The image was taken with the narrow angle camera on July 3, 2004, from a distance of about 789,000 kilometers (491,000 miles) from Titan and at a Sun-Titan-spacecraft, or phase, angle of 114 degrees. The image scale is 4.7 kilometers (2.9 miles) per pixel.

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 Cassini orbiter and its two onboard cameras were designed, developed and assembled at JPL. The imaging team is based at the Space Science Institute, Boulder, Colo.

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

Credit: NASA/JPL/Space Science Institute

http://www.nasa.gov/mission_pages/ca.../pia06090.html
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Old 30.07.2004, 19:42   #6
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Saturn's Magnetosphere

Saturn's magnetosphere is seen for the first time in this image taken by the Cassini spacecraft on June 21, 2004. A magnetosphere is a magnetic envelope of charged particles that surrounds some planets, including Earth. It is invisible to the human eye, but Cassini's Magnetospheric Imaging Instrument was able to detect the hydrogen atoms (represented in red) that escape it. The emission from these hydrogen atoms comes primarily from regions far from Saturn, well outside the planet's rings, and perhaps beyond the orbit of the largest moon Titan.

The image represents the first direct look at the shape of Saturn's magnetosphere. Previously, NASA's Voyager mission had inferred what Saturn's magnetosphere would look like in the same way that a blind person might feel the shape of an elephant. With Cassini, the "elephant" has been revealed in a picture.

This picture was taken by the ion and neutral camera, one of three sensors that comprise the magnetospheric imaging instrument, from a distance of about 3.7 million miles (about 6 million kilometers) from Saturn.

The magnetospheric imaging instrument will continue to study Saturn's magnetosphere throughout the mission's four-year lifetime. 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 Cassini orbiter was designed, developed and assembled at JPL. The magnetospheric imaging instrument team is based at the Johns Hopkins University, Laurel, Md.
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Old 30.07.2004, 20:23   #7
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Cassini Mission

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Exploring Saturn's Moons

Titan

Discovered in 1655 by the Dutch astronomer Christiaan Huygens, Titan is the biggest of the 31 known moons orbiting Saturn. It is a cold world enclosed by a thick, hazy atmosphere impenetrable by optical instruments.


Titan taken by Voyager 2

With a diameter of 5,150 kilometers (3,200 miles), Titan is the second largest moon in the solar system. It's bigger than our own moon and even bigger than the planet Mercury. Only Jupiter's moon Ganymede is larger than Titan, with a diameter barely 112 kilometers (62 miles) greater. Temperature at the surface is about minus 178 Celsius (minus 289 Fahrenheit).

Titan orbits Saturn at a distance of about 1.2 million kilometers (745,000 miles), taking almost 16 days to complete a full orbit -- 15.94 days to be exact.

Titan is of great interest to scientists because it is the only moon in the solar system known to have clouds and a mysterious, thick, planet-like atmosphere. In 1980, during a flyby of Titan, NASA's Voyager 1 tried to take close up images of the natural features of the landscape but it wasn't able to penetrate the thick clouds. The only results netted were slight color and brightness variations within the atmosphere. Titan's atmospheric pressure is about 60 percent greater than Earth's -- roughly the same pressure found at the bottom of a swimming pool.

In 1994, NASA's Hubble Space Telescope recorded pictures of Titan, which suggested that a huge bright "continent" exists on its hemisphere that faces forward in orbit. These Hubble results don't prove that liquid "seas" exist, however; only that Titan has large bright and dark regions on its surface.

The instruments aboard the Cassini-Huygens spacecraft are designed to uncover many of Titan's characteristics. During dozens of flybys, the Cassini orbiter will map Titan with cloud-penetrating radar and collect atmospheric data. The Huygens probe will dive through Titan's dense atmosphere with instruments capable of analyzing its components.

The instruments aboard the Cassini-Huygens spacecraft are designed to uncover many of Titan's characteristics. During dozens of flybys, the Cassini orbiter will map Titan with cloud-penetrating radar and collect atmospheric data. The Huygens probe will dive through Titan's dense atmosphere with instruments capable of analyzing its components.

Other Moons

Besides Titan, there are at least 30 other moons orbiting Saturn. Some carry exotic names such as Prometheus, Pandora, Enceladus and Hyperion, others are known by plain letter and digits codes, as in S/2000 S4 and S/2000 S5.


Some of Saturn's most interesting moons.

These moons vary considerably in shape and size. Some appear to be porous, icy bodies with craters, ridges and valleys -- others show corrugated, irregular terrain. Some appear to have formed billions of years ago, while others appear to be part of a bigger, fragmented body. Some moons appear to have rocky surfaces, and might be covered by organic material similar to the complex substances found in the most primitive meteorites. For example, the closest large moon of Saturn, Enceladus, appears to have a very bright, white surface, as it reflects almost 100 percent of the sunlight that hits it. Because Enceladus reflects so much sunlight, the surface temperature is only minus 201 Celsius (minus 330 Fahrenheit).


Artist's rendition of icy Enceladus.

According to images recorded by Voyager 2 in 1981, Enceladus has fissures, plains, corrugated terrain and other crustal deformation. All of this indicates that the interior of the moon may be liquid today, even though it should have frozen eons ago.

For the most part, very little is known about Saturn's moons, except through data gathered that measures their brightness. These moons' estimated sizes are based on assumptions of their reflectivity.

These 31 known moons vary greatly in their orbital positions within the Saturn system -- some are as close as 133,600 kilometers (83,015 miles) to the planet, others as far as almost 13 million kilometers (about 8 million miles). During its four-year mission in this immense region, the Cassini spacecraft will extensively photograph these moons, and collect data that will increase our understanding of their composition.
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Old 04.09.2004, 09:52   #8
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September 2, 2004

by Doug Vakoch
SETI Institute

In a startling follow-up to last week’s announcement that a “super-Earth” has been discovered around a nearby star, additional teams of astronomers have announced that two more planets of similar size have been detected. Of the most recent discoveries, one circles a sun-like star, while the other orbits a red dwarf star. Both newly announced planets are markedly smaller than the vast majority of other extrasolar planets so far detected, being roughly twenty times the mass of Earth – comparable to the size of Neptune. “This discovery shows that, as we expected, our galaxy is rich in planets much like the Earth,” explains astronomer Frank Drake, the Director of the SETI Institute’s Center for the Study of Life in the Universe.

“If you look at the 135 or so extrasolar planets found so far, it’s clear that nature makes more of the smaller planets than the larger ones,” says Geoff Marcy of the University of California at Berkeley, a leader of the team that discovered a planet around the red dwarf star Gliese 436, located 33 light years from Earth. “We’ve found more Saturn-size planets than Jupiter-size planets, and now it appears there are more Neptune-size planets than Saturn-size. That means there’s an even better chance of finding Earths, and maybe more of them than all the other planets we’ve found so far.”

“Ten years ago not a single planet was known to orbit a solar type star, other than those in our solar system,” says Steven J. Dick, NASA Chief Historian and author of the recently-published book The Living Universe: NASA and the Development of Astrobiology. “These newly discovered ones are the closest yet to the Earth in size. It is one more step in the exciting search for extraterrestrial life, which NASA supports through its astrobiology program.”

Paul Davies, P rofessor of Natural Philosophy in the Australian Centre for Astrobiology at Macquarie University, suggests that the recent discoveries have profound implications for theories of how planets form. Focusing on ways that the recent observations challenge our current understanding of planetary systems, Davies contends that “these latest observations confirm that large planets orbiting close to the parent star are a common feature of planetary systems. Such a configuration flies in the face of the orthodox theory of planet formation, and looks set to trigger a revolution in our understanding of how and where planets form.”

Other Earths?
But exactly how Earthlike are these newly discovered planets? That remains open to debate. “All exoplanets found so far are almost certainly gas giants,” says Marcy, speaking about earlier discoveries of planets around other stars. “But these new ones are a puzzle,” he continues. “They could be gaseous like Jupiter, but they also could have a rock-ice core and a thick envelope of hydrogen and helium gas, like Neptune. Or they could be a combination of rock and ice, like Mercury.”

All three of the Neptune-sized planets announced recently were discovered using the “radial velocity” approach. As planets orbit their stars, they cause slight perturbations in the star relative to the Earth. This slight rhythmic movement, alternately toward and away from the Earth, shows up as changes in the spectral emissions of the stars. By seeing how much time passes before the pattern repeats, scientists can determine how long it takes for the planet to complete a full orbit.
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Old 04.09.2004, 09:56   #9
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Space signal studied for alien contact

Thursday, September 2, 2004 Posted: 9:52 AM EDT (1352 GMT)

http://www.cnn.com/2004/TECH/space/0...eut/index.html

LONDON, England (Reuters) -- An unexplained radio signal from deep space could -- just might be -- contact from an alien civilization, New Scientist magazine reported on Thursday.

The signal, coming from a point between the Pisces and Aries constellations, has been picked up three times by a telescope in Puerto Rico.

There are other explanations besides extraterrestrial contact that may explain the signal. New Scientist said the signal could be generated by a previously unknown astronomical phenomenon or even be a by-product from the telescope itself.

But the mystery beam has excited astronomers across the world.

"If they can see it four, five or six times it really begins to get exciting," Jocelyn Bell Burnell of the University of Bath in western England told the magazine.

It was broadcast on the main frequency at which the universe's most common element, hydrogen, absorbs and emits energy, and which astronomers say is the most likely means by which aliens would advertise their presence.

The potentially extraterrestrial signals were picked up through the SETI+home project, which uses programs running as screensavers on millions of personal computers worldwide to sift through the huge amount of data picked up by the telescope.
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Old 04.09.2004, 10:40   #10
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Scientists Discover First of a New Class of Extrasolar Planets

http://www.nasa.gov/vision/universe/...ar-083104.html

Results from NASA-funded research have put humankind just a little closer to answering the age old question, "Are we alone in the universe?"

Astronomers have announced the first discovery of a new class of planets beyond our solar system. The Neptune-sized planets -- about 10 to 20 times the size of Earth -- are far smaller than any of the previously detected extrasolar "gas giants." It's even possible that the new class of planets is rocky, like Earth and Mars, and scientists are enthusiastic about the discoveries that may come next.


Image above: This artist's concept shows the newly discovered Neptune-sized extrasolar planet circling the star Gliese 436. In this depiction, the planet appears gaseous like Jupiter, with a cloudy atmosphere. In reality, astronomers do not know if this planet is gaseous, or rocky, like Earth and Mars. + Click for larger image. Image coutesy: NASA.
More images and animations are available at http://planetquest.jpl.nasa.gov/news/ssu_images.html


"These Neptune-sized planets prove that Jupiter-sized, gas giants aren't the only planets out there," Dr. Geoffrey Marcy, one of the planet co-discoverers, said. His partner, Dr. Paul Butler, added, "We are beginning to see smaller and smaller planets. Earth-like planets are the next destination."

In addition, one of the new planets joins three others around the nearby star 55 Cancri to form the first known four-planet system.

The discoveries consist of two new planets. They were discovered by the world renowned planet-hunting team of Butler and Marcy of the Carnegie Institute of Washington and University of California, Berkeley, respectively; and Barbara McArthur of the University of Texas, Austin. Both findings were peer- reviewed and accepted for future publication in the Astrophysical Journal. NASA and the National Science Foundation funded the research.

Because the new planets are smaller than Jupiter, it is possible they are made of rock, or rock and ice, rather than gas. According to the scientists, the planets may have, like Earth, formed through gradual accumulation of rocky bodies. "A planet of Neptune's size may not have enough mass to hold onto gas, but at this point we don't know," Butler said.


Image above: This illustration compares the size of the newfound Neptune-sized planets beyond our solar system to the sizes of Earth and Jupiter. The new planets are only about 20 times the mass of Earth, or about two times the actual size or diameter - much smaller than the majority of Jupiter-sized extrasolar planets detected so far. Image coutesy: NASA/JPL.

"NASA, along with our partner NSF, is extremely proud of this significant planetary discovery," said Al Diaz, Associate Administrator of NASA's Science Mission Directorate. "The outcome of the tremendous work of the project scientists is a shining example of the value of space exploration."

Future NASA planet-hunting missions, including Kepler, the Space Interferometry Mission and the Terrestrial Planet Finder, will seek such Earth-like planets. Nearly 140 extrasolar planets have been discovered.

Both of the new planets stick very close to their parent stars, whipping around them in a matter of days. The first planet, discovered by Marcy and Butler, circles a small star called Gliese 436 about every two-and-one-half days at just a small fraction of the distance between Earth and the Sun, or 4.1 million kilometers (2.6 million miles). This planet is only the second known to orbit an M dwarf, a type of low-mass star four-tenths the size of our own sun. Gliese 436 is located in our galactic backyard, 30 light-years away in the constellation Leo.

The second planet, found by McArthur, speeds around 55 Cancri in just under three days, also at a fraction of the distance between Earth and the sun, at approximately 5.6 million kilometers (3.5 million miles). Three larger planets also revolve around the star every 15, 44 and 4,520 days, respectively. Marcy and Butler discovered the outermost of these in 2002. It is still the only known Jupiter-like gas giant to reside as far away from its star as our own Jupiter. The 55 Cancri is about 5 billion years old, a bit lighter than the sun, and is located 41 light-years away in the constellation Cancer. "55 Cancri is a premier laboratory for the study of planetary system formation and evolution," McArthur said.

Both discoveries were made using the "radial velocity" technique, in which a planet's gravitational tug is detected by the wobble it produces in the parent star. Butler, Marcy and collaborators, including Dr. Deborah Fischer of San Francisco State University and Dr. Steven Vogt of the University of California, Santa Cruz, discovered their "Neptune" after careful observation of 950 nearby stars with the W.M. Keck Observatory in Mauna Kea, Hawaii. They were able to spot such a relatively small planet, because the star it tugs on is small and more susceptible to wobbling.

McArthur and collaborators Drs. Michael Endl, William Cochran and Fritz Benedict of the University of Texas discovered their "Neptune" after obtaining over 100 observations of 55 Cancri from the Hobby- Eberly Telescope at McDonald Observatory in West Texas. Combining this data with past data from Marcy, Fischer and Butler from the Lick Observatory in California, and archival data from NASA's Hubble Space Telescope, the team was able to model the orbit of 55 Cancri's outer planet. This, in turn, allowed them to clearly see the orbits of the other three inner planets, including the new Neptune-sized one.

More images and animations are available at http://planetquest.jpl.nasa.gov/news/ssu_images.html .

Information about NASA's hunt for extrasolar planets is available at http://planetquest.jpl.nasa.gov.


Whitney Clavin
NASA's Jet Propulsion Laboratory

Don Savage
NASA Headquarters
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Old 01.11.2004, 17:25   #11
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Cassini finds evidence Titan may be geologically alive!

http://www.cnn.com/2004/TECH/space/1....ap/index.html

Thursday, October 28, 2004 Posted: 10:19 PM EDT (0219 GMT)

PASADENA, California (AP) -- The Cassini spacecraft is sending back evidence that Saturn's planet-size moon Titan is geologically alive, possibly with liquids moving on its surface, scientists said Thursday.



Images made from radar beams bounced off Titan during Cassini's close flyby this week revealed such surface details as a round basin, narrow miles-long linear "streaks," and a cat-shaped region of what could be the moon's theorized lakes of liquid methane and ethane.

Scientists had been reluctant to draw conclusions about surface features from pictures taken through Titan's hazy atmosphere. But they sounded more confident after radar data arrived late Wednesday and was processed into images depicting terrain in shades of black and white.

"We are seeing much higher resolution here ... and we are seeing detailed features," said Charles Elachi, JPL's director and team leader for Cassini's radar instrument, which imaged a swath of Titan about 75 miles wide and 1,240 miles long.

Elachi said there was "high confidence" in the evidence of geologic activity, noting the long linear features as an example.

The possible region of lakes was depicted as very dark, which in radar data is a characteristic of a signal bouncing off a very smooth surface like a liquid. The region was named "Si-Si the Cat," after a scientist's young daughter who noticed it resembled a "Halloween cat," Elachi said.

Cassini reached Saturn this summer on a $3.3 billion international mission to study the planet's system for four years.

Unlike the airless moons and space rocks that NASA can photograph with startling clarity, Titan, hundreds of millions of miles from Earth, has long stymied scientists because its surface is shrouded by a thick atmosphere of nitrogen and methane.

That has forced scientists to create theories about the surface from observations of the hydrocarbon-laced atmosphere. Scientists believe seas or lakes of methane could form as organic compounds fall out of the atmosphere and collect on the surface.

Imaging team member Alfred McEwen of the University of Arizona presented information from optical pictures taken during Cassini's dash past Titan showing streaks in the atmosphere over the north polar region and east-to-west streaks on the surface.

The surface streaks are believed to be from movement of material, and given their consistency over a large scale, wind is believed to be the primary cause, McEwen said.

"What Cassini has shown us this week ... (is that) Titan is an extremely dynamic and active place, not simply in its atmosphere but on its surface as well," said Jonathan Lunine, an interdisciplinary scientist.
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