Object of the Month

 
Carrie - a work experience student - talks about her choice of the Odessa Meteorite as the Object of the Month for the Lapworth Museum of Geology
Video transcript here

The Odessa Meteorite

Ector County, Texas, U.S.A.

This meteorite sample came from an impact which is estimated to have taken place around 60,000 years ago during the Pleistocene, near what is today Odessa in Texas. There are a number of craters recognisable at the site, the largest around 500 feet in diameter, and over 1200 meteorites have been collected from the surrounding area with the largest being around 135Kg in weight.

Like most meteorites, the meteoroid that it came from is thought to have been material left over from the formation of the Solar System which crossed the Earth’s orbit, was pulled in by the Earth’s gravity, and broken up during the journey through the atmosphere.

It is an iron (siderite) meteorite, specifically a coarse octahedrite, with around 7 or 8% nickel and a kamacite lamellae width in the characteristic Widmanstätten structure of 1.6mm. This structure can be seen on the surface of the meteorite – interlocking bands (lamellae) of kamacite and taenite formed by the slow cooling (at a rate of 100-10,000°C/million years) of the nickel and iron alloys.

This slice also displays the classic dark fusion crust around its edge, caused by surface melting due to the extreme temperatures encountered when entering the earth’s atmosphere.