This meteorite, a basalt lava rock nearly indistinguishable from many
Earth rocks, provided the first strong proof that meteorites could come
from Mars. Originally weighing nearly 8 kilograms (17.6 pounds), it was
collected in 1979 in the Elephant Moraine area of Antarctica. The side of
the cube at the lower left in this image measures 1 centimeter (0.4
inches).
This picture shows a sawn face of this fine-grained gray rock. (The
vertical stripes are saw marks.) The black patches in the rock are melted
rock, or glass, formed when a large meteorite hit Mars near the rock. The
meteorite impact probably threw this rock, dubbed "EETA79001," off Mars
and toward Antarctica on Earth. The black glass contains traces of
martian atmosphere gases.
The Mars Exploration Rover Opportunity has discovered that a rock
dubbed "Bounce" at Meridiani Planum has a very similar mineral composition
to this meteorite and likely shares common origins. Bounce itself is
thought to have originated outside the area surrounding Opportunity's
landing site; an impact or collision likely threw the rock away from its
primary home.