| Moon rocks on Earth
< Lunar geology During
the bombardment of the Moon, the largest impacts were powerful enough
to threw pieces of the Moon out into space. Some of them found
themselves in orbit around the Earth, eventually falling to the surface
where they can now be collected as meteorites. In total,
around
33 kilograms of lunar rock have been collected in this way! The
meteorites contain lots of different minerals and rock types, which can
teach us about different parts of the Moon, although having said that,
some meteorites are identical to others, telling us that they came from
the same meteoroid that broke apart in the Earth’s atmosphere
as
it came down to the surface. It’s impossible to exactly
pinpoint
the starting point of any given meteorite because such a small number
of sites were visited by the Apollo astronauts, so we only know in
detail about a handful of locations. It is easy to tell if a meteorite
has come from either the mare or the highlands, though, and because
mare
dominate the near side of the Moon, any meteorites containing mare-like
compositions must have come from the near side.  Lunar meteorite SaU 169 as it was
found
in Oman There is
only one example where scientists think they have pinpointed a precise
location for a lunar meteorite, but there is much controversy
surrounding the claim. Meteorite
SaU 169, which was found in Oman in
2002, has such a unique composition that some meteorite specialists
think it came from an equally unique location on the Moon, a place near
the Lalande impact crater near to the Imbrium basin. The meteorite
shows evidence of four different impact events, including the formation
of the Imbrium basin itself. It was also involved in two more impact
events, including the formation of Lalande crater, before being ejected
from the lunar surface nearly 10,000 years ago.
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