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 – ...

The planets in our solar system orbit the sun essentially along a line across the sky in a plane called the ecliptic. For that reason, planets in our Earthly sky always appear somewhere along a ...

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 ...

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 ...

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.

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 ...

Scientists believe that two asteroids might be fragments of long-lost "planetary embryos" from the early solar system.

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 ...

The seven planets will not be perfectly aligned, but will appear in an arc across the sky due to their orbital plane in the Solar System. The world will witness a rare sighting in the sky in late ...

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 ...