The newly identified cluster of Kuiper Belt objects lies about 4 billion miles from the Sun, offering fresh clues about how ...

There could be a ninth planet in our solar system that's lying in wait to be discovered - and no, it's not Pluto. Our solar ...

Something is throwing icy bodies past Neptune, and scientists have an interesting idea about what it might be. When you purchase through links on our site, we may earn an affiliate commission. Here’s ...

UNDATED (WKRC) - Astronomers recently made an important discovery when they found a rare "in-sync" solar system with six planets all moving in one big grand harmony, completely untouched by outside ...

TEMPE, Ariz. a Quick: What’s the order of the planets in the solar system? Need a little help? Maybe the following mnemonic rings a bell: “My Very Educated Mother Just Served Up Nine Pizzas.” It’s ...

Super-Earths and sub-Neptunes, planets with sizes between Earth and Neptune, constitute approximately one-third of known exoplanets but are absent in our solar system. Their prevalence elsewhere and ...

Astronomers using planet-hunting satellites have discovered a rare solar system with six planets moving completely in sync with one another, as if they were untouched by any outside force since being ...

So far, humanity has yet to find its first "exomoon"—a moon orbiting a planet outside of the solar system. But that hasn't ...

Short-lived radioisotopes such as aluminum-26 influenced early solar system heat, water retention and the formation of Earth-like rocky planets, according to meteorite analyses and models.

The International Astronomical Union (IAU) defines a planet as a celestial body orbiting the Sun, possessing sufficient mass for a nearly spherical shape, and having cleared its orbital neighborhood ...