For decades, we believed there were nine planets in our solar system—until Pluto was reclassified in 2006. But what if ...

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

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

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.

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 ...

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 ...

Canadian astronomers have taken an extraordinary step in understanding how planets are born, using the James Webb Space ...

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 ...

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 ...

a rare seven-planet alignment visible in the sky. But such events are not just a spectacle for stargazers – they can also have a real impact on our Solar System and offer the potential to gain ...

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