Astrobiologists say we could find evidence of microbial life within the next 10–20 years. What does that mean? Where are we ...

Life on Earth may not have started here at all. A scientist says alien intervention is unlikely but still possible, reshaping the debate on our true origins.

Carl Grillmair, a renowned Caltech scientist who discovered water on a distant planet, was fatally shot at his Los Angeles-area home. Authorities arrested a suspect in connection with the killing.