Does our Solar System have 9 planets or only 8? Astronomers have gone back and forth on that a lot, with Pluto now being classified as a dwarf planet. However, out beyond Neptune there could be ...

The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit ...

The building blocks of life could have been delivered to Ceres by one or more space rocks from the outer asteroid belt.

Gaia-4b is considered a super-Jupiter planet, a relatively cold gas giant, orbiting its star over 570 Earth-days. That star ...

For decades, Pluto was celebrated as the ninth planet of our solar system. However, in 2006, the International Astronomical ...

In August 2006, the International Astronomical Union made the controversial, but correct, decision to demote Pluto from its ...

Our solar system contains planets, dwarf planets, asteroids and comets — but only one world is known to harbor life. Scientists have long debated whether Earth is truly unique. Perhaps our planet just ...

The organic ingredients to life, hints to where Earth’s water came from, and the fundamental building blocks of our planet ...