There has been much excitement this week about the possibility of water -- and life -- on some newly discovered exoplanets. But we can look closer to home for evidence of ET.
If there's life on one of the Earth's seven sisters, chances are it has spread to all of them.
Exciting new research suggests that a crater on Ceres may be a cradle of life.
Funding has been agreed for ESA's ExoMars rover, giving new hope that Europe could find life on Mars.
Astronomers are excited about sub-surface oceans in the solar system, as they may support life. Now Pluto joins the club.
ESA's second mission to Mars has become prey to the curse of the Red Planet – although the orbiter is heading for success, the Schiaparelli lander seems to have disappeared.
Rocks on Mars are surprisingly similar to those on Earth.
Scientists have finally found an Earth-like planet we may actually be able to visit.
It may make sense for intelligent aliens to have two eyes and ears on one head, and to walk upright. But other particulars – including their colour – are more open to speculation.
Some argue that it would be impossible to understand an alien language, as it wouldn't have the same grammar as humans use. But others are more optimistic.
Whether it's Hillary Clinton's courting the UFO vote or Donald Trump's lending credibility to various conspiracy theories, the "triumph of reason" seems to have gone by the wayside.
In a world of blogs, twitter and open data, scientists need to think again about how they'd communicate a discovery of alien life.
A philosopher argues that now is the time to figure it out, before we make the inevitable discovery of extraterrestrial life.
There are technological ways to hide a planet from intergalactic detection – as well as ways to signal that we're just sitting here, eager for contact.
Study suggests that comets and meteorites could have seeded planets beyond our own solar system with life.
If we do find life on Mars, it will be difficult to prove that we didn't bring it there from Earth. An insider talks us through what's at stake.
As the list of known planets beyond our solar system grows, the search for their moons is intensifying. One reason: they might hold the key to finding life elsewhere in the universe.
Have we been jumping to conclusions about water on Mars?
Dust from pulverised comets rather than an alien megastructure could explain odd flicker of distant star.
New research gives a clue about what happens when there are two habitable worlds in the same solar system.