Reflections on the habitability of Earth

We know the Earth is habitable because—well, here we are. But would it look like a good candidate for life from hundreds of light-years away?

The aliens are silent because they're dead

Life on other planets would likely be brief and become extinct very quickly, say astrobiologists from The Australian National University (ANU).

Nitrogen may be a sign of habitability

We might commonly think of Earth as having an oxygen-dominated atmosphere, but in reality the molecule makes up only a fifth of our air. Most of what surrounds us is nitrogen, at 78 percent. Astrobiologists are beginning ...

Humans evolved to get better sleep in less time

Insomniacs take heart: Humans get by on significantly less sleep than our closest animal relatives. The secret, according to a new study, is that our sleep is more efficient.

Cassini plunged into icy plumes of Enceladus

The Cassini spacecraft took a daring plunge into the icy geysers of Saturn's moon Enceladus this week in search of telltale signs of a habitable environment.

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