I did two related things yesterday: I wrote about the asteroid Vesta, and I went to the Denver Gem and Mineral show. How are those tied together? Glad you asked. In the last paragraph of the Vesta post, I said we have samples of Vesta that fell as meteorites. As it happens, they had a sample of one of those rocks at the show! Here it is:
Other such meteorites have been found on Earth as well, and are generally referred to as HEDs, short for Howardite/Eucrite/Diogenite -- the three main types of these rocks. So how do we know these meteorites were once part of Vesta? A couple of ways, actually, but they rely on spectroscopy. That's the process of taking the light from an object and breaking it up into individual wavelengths (using a prism or a finely etched grating, for example), essentially creating a rainbow with as ...
