Fragments of asteroid with mystery origin are found outside Berlin

Scientists have found pieces of a meteorite that fell near Berlin just after midnight on January 21. It is a rare find, from an asteroid that was identified just before it entered Earth's atmosphere. Only a handful of such events in the recent past have allowed astronomers to trace an incoming rock's origin in the solar system.

Early analysis of the fragments has shown something equally rare. The meteorite is an aubrite, a class with unknown origins that some scientists argue may be pieces of the planet Mercury. They are so rare that they made up just 80 of the 70,000 or so meteorites that were collected on Earth before last month's event.

"It's really exciting," said Sara Russell, a meteorite expert at the Natural History Museum in London. "There are very, very few aubrites."

The asteroid that became the meteorite (or rather fragments of meteorite) was...