Stargazers will be treated to a rare seven-planet alignment in February. This is what scientists hope to learn.

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 seven of the other planets in our solar system are about to become visible at once in a great planetary alignment – ...

The eight major planets of our Solar System orbit the Sun in the same flat plane, and all at different speeds. Mercury, the closest planet to the Sun, completes an orbit – a year for the planet ...

Simpson and Chen ran mathematical models looking at how differently sized Earth-like worlds would have affected the rest of our Solar System. The planet sizes tested were 1 percent of Earth's mass, ...

Have you ever wondered why the planets in our solar system align along a flat plane? Discover the science behind this cosmic arrangement, from the formation of the protoplanetary disk to the forces ...

"We are the first mission to be able to track space weather events in three dimensions routinely across the solar system." ...

An asteroid that orbited near Earth for a few months as a mini-moon may be a chunk of the moon that was blasted off by an impact thousands of years ago.

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.

The eight major planets in our Solar System orbit the sun on the same flat plane but at vastly different speeds. Mercury, being the closest to the sun, completes an orbit in only 88 days ...

This extraordinary spectacle, known as a great planetary alignment, will see seven visible planets scattered across the sky. The eight planets in our solar system orbit the sun in roughly the same ...