The first step to figuring out if we found alien life is to define what we mean by living.

There's much more to whether a planet is habitable than its distance from a star...

The Catholic Church is telling believers that any discovery of alien life fits firmly in their dogmas.

Life, uh, finds a way. But how would it finds its way on Mars?

We spend a lot of time thinking about intelligent aliens. We should invest a lot more thinking about feral ones.

Creationists and theists are trying to equate the search for life with a rebellion against a belief in God.

If we really want to find extraterrestrial life, we need to broaden our horizons and consider how alien chemistry could be different from our own.

Simulations are great starting points. But there are only so many conclusions we can draw from them.

The concept of a habitable zone is useful, but too vague to mean much when we're looking for alien life.

Could life on Earth have come here from another world? And could it travel from us to other solar systems?