New models suggest that Ceres, the asteroid belt's largest object, once had a radioactive core that could have sustained life in the dwarf planet's hidden subsurface ocean billions of years ago.

Astronomers say they have evidence that there may be a hidden planet in our Solar System. Named 'Planet Y', the Earth-sized ...

This iconic image marks the final visual record sent back by Voyager 2 before its optical cameras were permanently shut off to conserve the probe’s shrinking power supply.

On August 24, 2006, Pluto ceased to be considered a planet. A mixture of rock and ice located in the Kuiper Belt, a region of icy objects beyond the orbit of Neptune. This demotion ...

The autumnal equinox is on Sept. 22 — a day of equal daylight and darkness that happens twice per year. The fall equinox ...

The protoplanet, now named WISPIT 2b, was spotted using advanced adaptive optics on some of the world’s most powerful ...

A new study suggests the existence of Planet Y. This hidden planet may be affecting the Kuiper Belt. The gravity of Planet Y ...

Neptune is big, it’s blue, and it is a planet that can tear you apart if you happen to drop into one of its massive, ...

When NASA broke the news last week, astronomers and space fans alike did a double take: a brand-new moon hiding around Uranus, spotted not by a fly-by ...

Planet Nine was previously suggested as a possible explanation for distant orbital clustering. It was thought to be ten times Earth’s mass, orbiting far beyond Neptune.

Astronomers propose a new hypothetical planet, Planet Y, beyond Neptune, based on observed orbital anomalies in the Kuiper ...

Theories on planet formation are extensive, but evidence is sometimes lacking. It has now been observed how an exoplanet ...