Where's the best place to find a Meteorite? Antarctica!
It's not always easy to identify a rock as being a meteorite. For one, they
are extremely rare. But in Antarctica, they are easy to find. Even extremely
small meteorites pop out against the Antarctic white ice. Since Antarctica
never snows (most people don't know that), the meteorites could be sitting
for some time and remain uncovered.
In particular, as the ice flows towards the oceans, the movement
tends to concentrate the meteorites in places where the
ice flows up against mountains. Over 16,000 meteorites
have been collected so far. Antarctica is the main sight from
which most known meteorites have originated, thanks to
systematic recovery expeditions.
Most researchers didn't believe you could knock a piece off of
a big planetary body, and send it to Earth as a meteorite. In
1981,
that was proven to be false when this meteorite (on the right)
was found. Studies of the Apollo lunar specimens had revealed
a distinctive characteristic and this specimen was
a spitting image for one of the more common types found on the Moon. In a short
time researchers realized they might have samples of other
planets as well, including Mars.
When ALH84001 was first found in Antarctica in 1984, it was classified as a diogenite meteorite, and thought to have originated in the asteroid belt. Later, in 1994, studies of the isotopic ratios of the entrapped gases, specifically oxygen isotopes (see here), showed it to instead be one of the growing classes of Mars meteorites. It was soon after that that the most startling results on studies of ALH84001 began to surface.