* Astronomy

A speck of crystal that fell to Earth in a meteorite has been traced back to a red-giant star. It's not the same as having a sample return mission to, say, Aldebaran, but it's still pretty awesome: mounted on a gold pedestal in a laboratory in the Carnegie Institute of Washington and then bombarded by ions, a grain of less than a micrometer has confessed that it came from a different star. According to research published in the December 19 Astronomy & Astrophysics, the crystal probably formed near a star of intermediate mass, 4 to 7 times that of the Sun, which was nearing the end of its life and had entered the red-giant stage. Lead author Maria Lugaro, an Italian astronomer at Utrecht University in the Netherlands, says finding and analysing similar specks could yield important information about the conditions inside red giants. The speck in question has been christened OC2. No one knows precisely how it got to Earth. It was found in residue left after pieces of three stony meteorites, or chondrites, were dissolved in acid to analyse their contents. So OC2 may have landed in Bishunpur, India, in 1895, in Semarkona, India, in 1940 or in Krymka, Ukraine, in 1946. In any case, it was snugly embedded in stuff that once was part of an asteroid, which, before that, made up the Sun's primordial cloud of gas and dust. Sometime before the solar system's formation, OC2 must have drifted in and been mixed up in its history. Read more