Discoveries of new planets have revealed countless worlds much stranger than Earth. Some of these strange worlds don't have stars, others are made out of diamonds. Will we ever find a planet like Earth, or are these distant worlds stranger than fiction?

Dark matter is the biggest mystery of the cosmos. Scientists know that it has been vital to our universe since its birth, and new discoveries reveal that it could create black holes, cause mass extinctions, and might even shape life on Earth itself.

Life once existed on Mars, but a series of devastating mass extinctions have made present-day life nearly impossible. The latest science shows how Martian life keeps bouncing back as it transforms from a watery world like Earth into a desert planet.

The universe is a dangerous place, explore the deadliest spots in the cosmos; between earth and the edge of the universe, there are a million ways to die, and our crash test dummy is on a mission to reveal the worst.

Exploring the real-life Death Stars in the cosmos that could snuff out Earth without much effort; the science of the destructive power behind six of the deadliest stars; vampire stars; supernovas; rogue stars.

First close-up images of Pluto revealed the unimaginable secrets of this mysterious frozen world. Now, scientists investigate if Pluto is home to a warm ocean of liquid water beneath its surface, and whether this underground ocean could harbor life.

Recent evidence could explain how supermassive black holes grow so big; neither dark matter nor cannibalism can fully explain these beasts, but the latest science may finally provide an answer.

Scientists have discovered a mysterious ninth planet ten times the size of Earth on the very edge of our solar system; this strange world could have moons with extraterrestrial life.

From the furthest reaches of space to Earth's cosmic backyard, a countdown of the discoveries that changed everything humanity knows about the universe.