There have been questions about a mysterious ninth planet in our solar system for nearly a decade. Pluto was unseated as ...

Discovered in 1930, Pluto was long considered our Solar System's ninth planet, but was unseated in 2006 after the discovery ...

Earth has four seasons, but do other planets in our solar system also have hot summer days and cold winter nights?

open image in gallery Is there a possible ninth planet in our solar system ... first time in over 150 years, there is solid evidence that the solar system's planetary census is incomplete." ...

An alternate explanation that fits the evidence is that Vesta was once part of a planet – but which planet that might been ...

Warmer climates than Earth’s could accelerate life’s development, potentially increasing the number of planets with more ...

For years, astronomers have been searching for a ninth planet in our solar system (after giving Pluto the old heave-ho and demoting it to a dwarf planet) and now researchers say they’ve found a ...

To understand how chaotic the early solar system was, we need only gaze at the moon. Its cratered surface bears the scars of ...

Vesta had been thought to have been the last protoplanet, a leftover remnant from the early days of our solar system that never quite made it as a fully fledged planet for some reason. As the ...