Post by Craig on May 31, 2003 0:35:26 GMT -5
The Tagish Lake meteorite, which fell to Earth three years ago, is perhaps the best-preserved space rock and contains material that predates the solar system.
Fragments of the meteorite contain organic blobs, the first found in nature, that resemble those created in laboratory experiments intended to simulate conditions when life first arose, NASA researchers said.
"They would have been ready-made homes for early life forms," said Michael Zolensky, a geochemist at the space agency's Johnson Space Center in Houston, Texas.
"While not of biological origin themselves, these globules would have served very well to protect and nurture primitive organisms on Earth," added Zolensky, co-author of a report published this month in the International Journal of Astrobiology.
In January 2000, the estimated 200-ton meteorite exploded into a giant fireball and rained down fragments over a frozen lake in the Yukon Territory.
The fortuitous landing site and cautious recovery by a nearby resident helped preserve the fragile remnants, including frozen volatile gases that otherwise might have evaporated.
Usually such meteorites break up into dust during atmospheric entry, scattering their organic contents.
"If, as we suspect, this type of meteorite has been falling onto Earth throughout its entire history, then the Earth was provided with these hydrocarbon globules at the same time life was first forming here," Zolensky said.
Fireball over the Yukon from the estimated 200-ton space boulder
"We were exceedingly fortunate that this particular meteorite was so large that some pieces survived to be recovered on the ground."
Last year, researchers said the meteorite contains more pre-solar grains, which predate the birth of the solar system 4.6 billion years ago, than any other known space rock.
Such grains were produced in an ancient supernova, the fiery explosion of a dying star, which provided the raw materials for the sun, planets and other solar system objects, according to scientists.
Because this particular meteorite most likely came from the outer asteroid belt, scientists think similar organic material could have reached Jupiter and its moons, including Europa, which is thought to have conditions that could make it suitable to harbor primitive life.
"It is interesting to speculate about the presence of these organics in the ocean we believe may be present under the ice cap of this moon," Zolensky said.
Fragments of the meteorite contain organic blobs, the first found in nature, that resemble those created in laboratory experiments intended to simulate conditions when life first arose, NASA researchers said.
"They would have been ready-made homes for early life forms," said Michael Zolensky, a geochemist at the space agency's Johnson Space Center in Houston, Texas.
"While not of biological origin themselves, these globules would have served very well to protect and nurture primitive organisms on Earth," added Zolensky, co-author of a report published this month in the International Journal of Astrobiology.
In January 2000, the estimated 200-ton meteorite exploded into a giant fireball and rained down fragments over a frozen lake in the Yukon Territory.
The fortuitous landing site and cautious recovery by a nearby resident helped preserve the fragile remnants, including frozen volatile gases that otherwise might have evaporated.
Usually such meteorites break up into dust during atmospheric entry, scattering their organic contents.
"If, as we suspect, this type of meteorite has been falling onto Earth throughout its entire history, then the Earth was provided with these hydrocarbon globules at the same time life was first forming here," Zolensky said.
Fireball over the Yukon from the estimated 200-ton space boulder
"We were exceedingly fortunate that this particular meteorite was so large that some pieces survived to be recovered on the ground."
Last year, researchers said the meteorite contains more pre-solar grains, which predate the birth of the solar system 4.6 billion years ago, than any other known space rock.
Such grains were produced in an ancient supernova, the fiery explosion of a dying star, which provided the raw materials for the sun, planets and other solar system objects, according to scientists.
Because this particular meteorite most likely came from the outer asteroid belt, scientists think similar organic material could have reached Jupiter and its moons, including Europa, which is thought to have conditions that could make it suitable to harbor primitive life.
"It is interesting to speculate about the presence of these organics in the ocean we believe may be present under the ice cap of this moon," Zolensky said.