, July 19 -- Scientists have identified the rare type of meteorite that is believed to have struck Earth 66 million years ago, triggering the mass extinction that wiped out about 75 percent of all ...

Discover the 15 places in Arizona that feel like another planet in this ultimate Arizona travel guide! From towering ...

The asteroid that wiped out the dinosaurs was likely an exceptionally rare CO chondrite from a distant region of the solar system. Its unusual chemistry suggests that planet-cooling dust and debris, ...

The asteroid that ended the age of dinosaurs may have been far rarer, drier and less sulfur-rich than scientists once thought ...