Planets
- Earth
Killer space rock snuffed out ancient life
Rock fragments from Antarctica suggest a huge meteor struck Earth 250 million years ago.
By Emily Sohn - Planets
A planet from the early universe
Astronomers have found the oldest and most distant planet known in the universe.
By Emily Sohn - Planets
Melting Snow on Mars
Melting blankets of snow may have carved out Martian gullies.
By Emily Sohn - Planets
A planet’s slim-fast plan
A planet orbiting very close to its sun can quickly lose weight.
By Emily Sohn