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

All of our solar system’s planets are lining up to parade through the night sky at once. This extraordinary celestial event will see the sky scattered with seven visible planets in what is known ...

The four planet-strong "planet parade" currently visible to the naked eye in the night sky for a short time after sunset will ...

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.

A planet parade is when several of our solar system's planets are visible in the night sky at the same time. There will be six planets visible this time around, including Venus, Mars, Jupiter ...

Uranus and Neptune are there too, technically, but they don't appear as 'bright planets'," NASA's Preston Dyches explained in a stargazing video guide. Stock illustration of all the solar system's ...

This may explain the strange properties of the orbits of our solar system's planets, which are not quite perfectly circular, and all lie on slightly different planes. NASA artist’s conception of ...

The formation of our solar system from a singular nebula raises an intriguing question: why did each planet develop with a ...

On Feb. 24, from west to east, you can see Mercury, Saturn, Neptune, Venus, Uranus, Jupiter and Mars, all spanning 117.5°, ...

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.