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

All seven of the other planets in our solar system are about to become visible at once in a great planetary alignment – ...

Although the six planets - Venus ... and helium. It also is the coldest planet in our solar system, with temperatures reaching -370°F. Most of Uranus's matter is icy. Uranus has 28 known moons ...

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.

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

These embryos, somewhere between small planetesimals and fully formed planets, were abundant during the solar system's formative stages and played a critical role in planetary formation.

Mars, Venus, Jupiter and Saturn should be visible to the naked eye, but with a telescope you can spot Neptune and Uranus.

To better understand why the planets have variable compositions ... to the formation of the gas and ice giants in the outer solar system. This first-order model of planetary growth in the solar ...

Temperamental' stars that brighten and dim over a matter of hours or days may be distorting our view of thousands of distant planets, suggests a new study.

A new type of exoplanet has been discovered: Enaiposha, also known as GJ 1214 b. Long heralded as a mini-Neptune, new observations have indicated that it is a member of a category never seen before ...

From January to March, the night sky will host a spectacular parade of planets featuring Venus, Mars, Jupiter, Saturn, Uranus, and Neptune. The alignment peaks on January 25 and Mercury joins the ...