Feature Planetary Science

Mystery Meteorite

The case for (and against) a rock from Mercury

Unearthly green rocks (one shown) found in the western Sahara last year may hail from Mercury.

S. Ralew

By Alexandra Witze

- More than 2 years ago

There are rocks from the moon, rocks from Mars — and now, just maybe, a rock from Mercury.

From left: JPL/NASA; JPL/NASA; JHU-APL/NASA, Carnegie Institution for Science

In early 2012, a nomad in the western Sahara spotted some green stones scattered on the sand.