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

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 ...

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

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.

Beyond Neptune lies the Kuiper Belt, a vast region of icy bodies offering crucial insights into the solar system’s formation ... and the Planet Nine model was not designed to address the ...

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

Ptolemy’s model and many earlier ideas of the Solar System had the Earth at the centre of it. As observations of the motions of the planets became more detailed, the descriptions of the Solar ...