Asteroids that orbit close to the Earth inevitably cause us some anxiety due to the even remote possibility of a collision.

When Tim McCoy, curator of meteorites at the National Museum of Natural History, and his team began analyzing the minerals in the Bennu sample, they found something unexpected: sodium carbonate. “I ...

Bennu’s parent asteroid, which formed around 4.5 billion years ago, seems to have been home to pockets of liquid water.