New research suggests that a binary pair of Kuiper Belt objects, known as the Altjira system, is actually made up of three ...

Early in our Solar System’s history, bits of icy debris were scattered and then gradually coaxed into a spiral alignment in ...

A newly identified Kuiper Belt trio, possibly only the second of its kind, could provide strong evidence that these distant ...

Astronomers have discovered what they believed to be a rare stable trio of gravitationally bound Kuiper Belt objects, ...

Astronomers have revealed new evidence that there are not just one but four tiny planets circling around Barnard's Star, the second-nearest star system to Earth.

Ceres is a dwarf planet in the asteroid belt between Mars and Jupiter. It's the largest object in the asteroid belt and the closest dwarf planet to Earth.

With family wealth to back him, he founded an observatory in the western dark-sky desert of the U.S. and hoped to unlock the mystery of the Red Planet. He soon became fascinated by another cosmic ...

Mercury has a rocky surface when, facing the sun, can reach highs of 800 degrees while overnight lows could reach minus 290 degrees, according to the space agency. Venus holds the crown of the hottest ...

The Milky Way's tidal forces may be shaping the Oort Cloud's inner structure into a spiral shape.

Venus, Mars, Jupiter, Saturn, Uranus, and Neptune were already visible in the night sky after dusk this month, but Mercury joined them on Feb. 28. While it's common to see a few planets line up in the ...

In 2006, the International Astronomical Union (IAS) reclassified Pluto as a dwarf planet. That decision came several years after discovering the Kuiper Belt, a ring of icy and rocky objects 2.8 ...