Test your knowledge on our solar system, from the biggest and smallest planets to the behemoth mountain on Mars. When you purchase through links on our site, we may earn an affiliate commission.

Astronomers have seen the aftermath of two planetary pile-ups in the same turbulent star system — providing potential insights into how planets form 1. Observations from the early 2000s indicated that ...

Nothing manmade has reached further from Earth than the Voyager series of spacecraft. Hurtling away from the sun at 38,000 miles an hour, the duo have now traveled over 12 billion miles, with Voyager ...

The comet is the third object ever confirmed to have entered our cosmic neighborhood from elsewhere in the galaxy. Space telescopes and orbiters have been documenting the rare visit. A mysterious ...