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.

If you think auroras on Earth are a strange and mesmerizing sight, that's nothing like what occurs on the perplexing world of Uranus.

Scientists have confirmed a massive underground lava tunnel beneath Venus using radar data from NASA’s Magellan mission.

Arnie said, "Get your a* to Mars", but is it really a good idea? We asked the experts about our Martian future.

A US lawmaker says he has heard classified briefings describing an object of extraordinary size recovered outside the country. The claim has intensified demands in Washington for greater transparency ...