A magnitude-6.2 earthquake occurred off the northwestern coast of Costa Rica at around 12:43 Oct. 12. The epicenter was about 42 km (26 miles) northwest of Tamarindo, Guanacaste Province.
The tremor occurred at a depth of...
Researchers have used the chemical fingerprints of zinc contained in meteorites to determine the origin of volatile elements on Earth. The results suggest that without 'unmelted' asteroids, there may not have been enough of these compounds...
