We tend to assume that an alien civilization would have its own home world - but what if they didn't actually need one ?
The comet comes from an enigmatic and colossal cloud of planetesimals that surrounds our solar system.
This peculiar striped rock is quite unlike anything that scientists have ever seen before on the Red Planet.
The Moon will be joined by a second natural satellite for a short time beginning this Sunday.
Here on Earth we take day and night for granted, but such a cycle might not even exist on some planets.
An Australian researcher believes he knows what happened to the plane and why nobody has found the wreckage.
Humans may simply be unable to survive long term on other planets without a bit of genetic tinkering.
The smallest planet in our solar system may be hiding a treasure with a value beyond imagination.
The distances between stars are vast - but just how long would it take us to travel between them ?
If an alien civilization has terraformed the atmosphere of a distant planet, we may be able to find it.
The private jet and its passengers had vanished without a trace, leading to decades of fruitless searches.
Detecting underwater acoustic signals could provide scientists with new insights into plane crashes.
A planet thought to be the real-life equivalent of Spock's homeworld Vulcan might not actually exist after all.
China's answer to the X-37B is doing something in Earth's orbit and nobody is quite sure what that might be.
Luring inquisitive extraterrestrials to our planet using nuclear radiation seems like a bit of a shot in the dark.
A type of rare, though extremely energetic and deadly cosmic event is able to wipe out whole planets.
A gas discovered in the atmosphere of this distant extrasolar planet is 'only produced by life', say scientists.
A team of planetary scientists has found new evidence of an undiscovered planet in the outer solar system.
The SpaceX CEO has some ambitious plans to build a thriving city on the Red Planet within as little as 20 years.
Today, we are the only human species left on the planet - but what was it that made us so special ?