NWA 1837 Olivine Diogenite Space Rock

The outer crust, as found in the Western Sahara.

It came from Vesta, the largest and brightest asteroid in the asteroid belt and the second largest body overall (after the dwarf planet Ceres), with an average diameter of about 525 km (326 miles). That is pretty close to the size of the State of Colorado.

A couple of billion years ago two massive impacts ejected part of Vesta’s mass and some of that material landed here on Earth as HED (howardite, eucrite, and diogenite) meteorites. It’s astonishing to consider that when you look at photographs of Vesta, or eve through a powerful telescope, the actual craters from which the HED meteorites were blasted out can easily be seen, such as Rheasilvia which is over 300 miles wide.

From the Meteorite Bulletin for NWA 7831:

History: Found buried in the ground near Chouichiyat in the Western Sahara on March 3, 2013, and excavated by a team of local people. Much of the material disintegrated into fragments upon excavation.

Stone meteorite – Diogenite, Achondrite: 5.5” by 4” by 2”, 1,301g, spent the past 17 years in the Michael Farmer “meteorite hunter” collection