- COPENHAGEN (Reuters)- A meteorite which crashed into Greenland last December
may have come from outside our solar system, the first time such a thing
has happened, a Danish astronomer said on Thursday.
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- A four-week expedition to the southwestern
part of the Greenland ice cap failed to find fragments of the meteorite
but returned home on Wednesday with about 200 samples of dust.
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- Astronomer Lars Lindberg Christensen
from Denmark's Tycho Brahe Planetarium astronomy centre, a member of the
seven-man expedition, said analysis of the dust samples could yield clues
to the origin of the meteorite.
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- ``It may have come with enough speed
that it actually originated outside our solar system. That would make it
a world first,'' he told Reuters by telephone.
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- The centre has collected more than 100
witness reports, three seconds of videotape and data from a U.S. defence
satellite of the meteorite's plunge through the Earth's atmosphere.
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- Calculations based on the video frames
of the meteorite's descent, which lit up the night sky over Greenland on
December 9, put its velocity at 56 km (35 miles) per second, or 1.5 times
the maximum speed of any known meteorite in our solar system, Christensen
said.
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- At such a speed, the object would have
disintegrated and the only traces would be dust, he said.
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- ``It also means that it is most likely
that the snow samples contain dust from the meteorite,'' he said.
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- The expedition collected enough dust
to allow the particles to be examined thoroughly, revealing their molecular
and atomic composition.
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- If analysis shows the dust particles
are more than 4.5 billion years old that would confirm the meteorite originated
in inter-stellar space, he said.
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- Our solar system is estimated to have
been formed 4.5 billion years ago.
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- Preliminary findings from the Niels Bohr
astro- and geophysics institute and the geological institute of the University
of Copenhagen could be ready in a matter of months, Christensen said.
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- Traces of more than 10,000 meteorites
have been found on Earth but the Greenland find is special because it is
one of the few that have been seen plunging from space.
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