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NASA IDENTIFIES EARTH'S BIGGEST KILLER On ancient Earth, long before the age of the dinosaurs, 90% of all sea creatures and 70% of land vertebrates became extinct in what geologists consider the blink of an eye. This was one of five great extinctions known to science, and the most devastating. At a NASA press conference (Feb. 22), Luann Becker presented a new kind of evidence that the cause of the Permian extinction event was a comet or asteroid impact.

Becker, of the University of Washington, studied cage-like carbon molecules called buckminsterfullerenes (or Buckyballs for their soccer-ball shape) found at sites in Japan, China and Hungary with exposed rock dating to the Permian - Triassic period (250 milion years ago). Analysis of the gases trapped in the center of the fullerenes, revealed a type of helium that is only formed inside carbon stars, revealing that the the molecules were delivered to Earth by an extraterrestrial object.

"It took us two years to do this research, to try to narrow it down enough so that we could see this fullerene signature," she said. The report of her findings appears in the latest issue of Science.
Graphic: Luann Becker, University of Wahington

Becker and NASA scientist Chris Chyba made clear that they see the impact not as the sole cause of the extinction, but as a mechanism that set off violent volcanic eruptions and other adverse effects, that combined, caused the rapid killing.

The extinction of the dinosaurs at the Cretaceous period (65 million years ago) has also been linked to extraterrestrial impact on evidence of a layer of the rare, cosmic element, iridium that spread around the globe. The circumstances of the impact events cause different ecological effects, depending, for instance, on whether the object hit a landmass or plunged into the ocean.

Now two of the five major extinctions are linked to comet or asteroid impacts, the cosmic environment must be recognized as a major factor in the evolution of life, including intelligent life, according to Chyba. "With major extinction events spaced, statistically, every 100 million years, -that's about the span of time allowed a species to develop a technological civilization capable of dealing with such an event. I think that increases the probability for (discovering) technological civilizations."

Links:
Asteroid or comet triggered death of most species 250 million years ago University of Washington.
Apocalypse Then Science@NASA

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SIGNALS FROM EROS The nimble NEAR Shoemaker spacecraft soft-landed, rather than crashed onto the surface of the asteroid Eros February 12. To the delight of mission scientists, data continues to be sent and received although the original mission is complete. An extension of 10 days was granted, which may be increased if good data continues to come in and room is available to track it using the busy Deep Space Network (DSN).

Links:
NEAR Collects Data From Asteroid's Surface Space.com

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WHEN GALAXIES COLLIDE Driven by gravitational attraction, our Milky Way galaxy and neighboring Andromeda move closer and closer together, dragging along their respective companion dwarf galaxies. In a few billion years, the two spirals will crash into each other, and when the violent encounter calms, the result will be a single elliptical galaxy surrounded by a cloud of satellite galaxies, according to a presentation at the American Association for the Advancement of Science meeting in San Francisco.

Ann Zabludoff said that astronomers really don't know if the environment in our galactic neighborhood is typical of other groups of galaxies. But if our local conditions are common in the universe, then this may be the type of environment where most galaxies evolve. According to the University of Arizona department of astronomy and Steward Observatory scientist, "The current guess is that our local galactic neighborhood is very common for galaxies, that most galaxies lie in local group type environments or perhaps even slightly more complex and populated neighborhoods."

Links:
Ann Zabludoff University of Arizona

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CONTACT LOST WITH PIONEER 10 After nearly 30 years of space travel, scientists report they have lost contact with the Pioneer 10 spacecraft. Its signal has grown weaker, its battery is almost dead, and it now takes almost 11 hours for a signal to reach the spacecraft from Earth and another 11 hours for scientists to hear back from it. They expect they have heard the last of this extraordinary robotic explorer.

When Pioneer 10 entered the asteroid belt on July 15, 1972 some months after its launch, it was the first time a spacecraft ventured into this supposedly hazardous territory. And when it flew by Jupiter at a distance of 81,000 miles on December 3, 1973, it was the first spacecraft to visit any of the outer planets, and it provided us with our first, astounding close-up of the giant planet. On June 13, 1983, it became the first human artifact to leave the Solar System. For many years it remained the most distant man-made object from the Earth. It was eventually surpassed by another traveler in the outer Solar System, Voyager 1.

Pioneer 10 is still carrying out its mission, as it carries a greeting from the people of Earth to other intelligent life it may encounter. The famous plaque, designed by the late Carl Sagan and Frank Drake, gives a graphic depiction of Earth's location, the human form and other basic information about Pioneer 10's homeworld.
Links:
An Aging Pioneer Fades Away The Planetary Society

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TWO-TIMING JUPITER On Saturday, December 30 the Cassini spacecraft, on its way to explore Saturn in 2004, makes its closest swing by Jupiter (6 million miles) to get a gravity boost. Already in orbit, is seasoned explorer, Galileo, which has been surveying the Jovian system since 1995. Mission scientists have been taking full advantage of the rare opportunity afforded by having two spacecraft studying a single planet. Among the recent goodies for the public are beautiful color pictures, movies of Jupiter's colorful, whirling atmosphere and eerie sounds from the planet. (To find these follow the links below.)

The Jet Propulsion Laboratory (JPL)hosted a press conference with both Cassini and Galileo mission scientists to discuss joint exploration which will continue over the next three months. Studies include Jupiter's energetic storm systems and the interaction of the solar wind with Jupiter's magnetic fields. Among the discoveries made, is evidence for a big cloud of material surrounding Jupiter that comes from the volcanoes on Io.
Jupiter Links:
Jupiter Millennium Flyby
Jet Propulsion Laboratory
Spacecraft Flyby paints new picture of Jupiter (CNN)

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