Ancient cosmic spherules

The discovery of cosmic spherules in sandstone over 1.4 billion years old from Finland has been reported by Deutsch, Greshake, Pesonen and Pihlaja. Cosmic spherules are an abundant form of extraterrestrial material and were first described in 1876. The new discovery provides a new way of tracking long term changes in atmospheric oxygen content, along with changes in the meteroroid population of the Solar System.