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 ...

Stargazers will be treated to a rare seven-planet alignment in February. This is what scientists hope to learn.

Scientists believe that two asteroids might be fragments of long-lost "planetary embryos" from the early solar system.

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

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

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

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

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

While the composition of gas and dust in a molecular cloud is fairly uniform, everything changes once a star begins to form.