IT’S been nearly 40 years since the first planet outside of our Solar System was discovered. Since then, more than 5,800 weird and wonderful worlds across 4,300 planetary systems have been lo… ...

Mercury is a mystery. It’s the smallest planet in our solar system, the closest to the Sun, and one of the most extreme. Its ...

Like the Star Wars planet, a distant world follows a path around two stars, both of them small, cool bodies called brown dwarfs.