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

Pluto isn't alone—it's part of the Kuiper Belt with possibly hundreds of other planet-sized objects. Because Pluto hasn't achieved gravitational dominance in its region, the International Astronomical ...

This provides another piece of the puzzle to understand how planets and ... Pluto-Charon ... that could reshape our understanding of the Earth-Moon system and the broader solar system.

According to a recent YouGov poll, 35% of Americans think Pluto is not a planet. But they are all wrong—kind of. To get to ...

As the gatekeepers to the Kuiper Belt, Charon and Pluto are a unique double dwarf planet system. When you purchase through links on our site ... largest moon in the solar system compared with ...

All of our solar system’s planets are lining up to ... apparent than during a planetary alignment. An alignment including all of the planets except Mercury is taking place in mid-January.

An object eight times the mass of Jupiter may have swooped around the sun, coming superclose to Mars' present-day orbit ...

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

However, this year a powerful new telescope is coming online that could prove once and for all that there really is a ninth planet in our Solar System. The same year that Pluto was ignominiously ...

Charon and Earth’s moon are both a large fraction of the size of the main body they orbit, which is unlike other smaller moons orbiting planets throughout our solar system. (Pluto has four ...