How to make a chondrule

摘要

Chondrules, the stony, seed-like grains in meteorites, were formed when some event melted rock in the solar nebula. The latest analyses narrow the possible 'when', 'where' and 'how' of that process. Open up almost any stony meteoi ite, as scientists have been doing foi more than 200 years, and you will find hundreds of millimetre-sized bits of rock These 'chondrules' (named after the Greek for seeds) were formed at the birth of the Solar System, and as such potentially bear witness to conditions - pressures, temperatures, chemical composition and so on-in the solar nebula. But obtaining that information depends on identifying how they formed, a topic tackled by Cuzzi and Alexander on page 483 of this issue.