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 ...

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

A U.S. scientist searching for a civilization across 7 Earth clones circling the red dwarf star TRAPPIST-1 says its own alien ...

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

The building blocks of life could have been delivered to solar system dwarf planet Ceres by one or more space rocks from the ...

Scientists studying samples that NASA collected from the asteroid Bennu found a wide assortment of organic molecules that ...