It's the oldest question on Earth. Where did we come from? Some people may thank a creator from above, but what if the hand that created humanity wasn't divine? What if aliens brought life to Earth? How could a meteor carry life to our planet?

But the real truth is that alien life on other planets could be even stranger than floating balloons or amorphous organisms floating in layers in water. Here on Earth, we have carbon-based life forms, but would they necessarily be elsewhere in the Universe?

How big would a telescope need to be to see Earth’s dinosaurs from 66 million light-years away? Think big—and then think bigger

If life exists elsewhere in the universe, researchers at the University of Washington are finding the clues on Earth to help understand where to look for it.

While idea may violate Occam’s razor, “it remains a speculative but logically open alternative,” says biologist Robert Endres.

Planet K2-18b, an apparent water world 124 light years away, has been seen as a promising location in the search for aliens, but telescopes on Earth failed to pick up any radio transmissions

Add Yahoo as a preferred source to see more of our stories on Google. A composite view of Mars taken by the Viking I and II probes. NASA/USGS In September, NASA announced the discovery of a possible sign of life, known as a potential biosignature, on Mars.

Documentary "Age of Disclosure" suggests imminent official confirmation of extraterrestrial presence on Earth. Features testimony from over 30 intelligence, military, and government officials, including Marco Rubio. Director Dan Farah claims, “We’re ...