The number of planets that orbit the sun depends on what you mean by “planet,” and that’s not so easy to define ...

When astronomers found a large world farther out than Pluto, it became one of the final nails in the coffin of our ninth ...

who orbit on average 150 times farther from the Sun than Earth. Among the half-dozen is the first known ETNO, the dwarf planet Sedna. The six curiosities that Brown and Batygin identified have ...

The cosmos, full of endless wonders and mysteries, keeps throwing us celestial curveballs. In a revelation that could reshape ...

The exoplanet HD 20794d swoops in and out of its habitable zone every few hundred days, making for an extreme climate.

An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit before shoving four of the solar system's planets onto a different course.

Astronomers have found evidence for what might be a planet with about half the ... The pulsar is locked in a 1.6-day orbit with one white dwarf, and both of them are orbited by another white ...

As the gatekeepers to the Kuiper Belt, Charon and Pluto are a unique double dwarf planet system ... Whereas a moon usually orbits a planet, both Pluto and Charon orbit a point in space between ...

The eight major planets in our Solar System orbit the sun on the same flat plane but at vastly different speeds. Mercury, being the closest to the sun, completes an orbit in only 88 days ...

Blue Origin’s reusable New Glenn rocket has successfully launched and reached orbit, though engineers failed to safely land the first-stage rocket booster back on Earth as hoped. Even so, ...