The oldest documented observation of an aurora may be in an ancient Chinese text.
The dino-killing asteroid lofted huge amounts of sulfur into Earth's atmosphere 66 million years ago, leading to rapid climate change.
Antarctica was warmer during the late Cretaceous period, a time when wildfire blazed through the region.
October's full moon and the peak of the Orionid meteor shower are happening on the same day this week.
A seismic image of central Louisiana reveals gigantic megaripple marks dating to the end of the dinosaur age.
About 100 million years ago, a gigantic meteorite collided with Australia, creating a 3-mile-wide impact crater.
Excluding Mercury, this newly discovered asteroid has the smallest known aphelion distance in our entire solar system.