An asteroid strike 66 million years ago caused millions of species to go extinct—including many mollusks. By studying the ...

However, you're more likely to read and hear about meteors, meteoroids, meteorites, comets, and asteroids online and in the ...

A once-mighty U.S. river is drying up far faster than climate models predicted, threatening ecosystems, agriculture, and water supplies for millions—experts warn urgent action is needed now. [disappea ...