How the Universe Works, Strangest Alien Worlds

Scientists have discovered evidence of a mysterious ninth planet on the very edge of our solar system, could its moons support extra-terrestrial life?

Supermassive black holes are so large they devour stars and shape galaxies. The latest science may answer why they grow so large.

Despite Pluto's appearance as a dark and frozen world, scientists are investigating whether there might be warm liquid water beneath the surface.

Countdown of NASAs top six the deadliest stars – 'vampire' stars that drain their neighbours, supernovas, and white dwarfs that destroy planets.

The Universe is a violent and dangerous place. From exploding stars and colliding galaxies to nebula shockwaves – what are the worst places in the Universe?

Once there was life on Mars – but scientists believe a series of devastating mass extinctions transformed a watery planet into a desert.

Dark matter is one of the greatest mysteries of the universe facing scientists today. Could it be the cause of supermassive black holes and mass extinctions?

Astronomers have discovered bizarre planets very different to Earth out in the galaxy, but will we ever locate a planet similar to our own?