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 ...

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 ...

Astronomers may have discovered a scrawny star bolting through the middle of our galaxy with a planet in tow. If confirmed, ...

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 ...

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

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 ...

While this parade of planets look to our eyes to be huddled in the evening sky, they are of course spread out across a vast chasm of space across the solar system, separated from each other by ...

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 ...

Stargazers will be treated to a rare alignment of seven planets on 28 February when Mercury joins six other planets that are already visible in the night sky. Here's why it matters to scientists.

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