The ancient Greeks proved over 2,000 years ago that the Earth was round and figured out how big it was by using simple observations of the Sun. But how do people know this today? When you drop ...

The International Astronomical Union (IAU) defined a dwarf planet in 2006 as a celestial body that orbits the Sun, is round in shape, but has not cleared its orbital neighborhood of objects of ...

Swinburne University of Technology provides funding as a member of The Conversation AU. Our Solar System is a pretty busy place. There are millions of objects moving around – everything from planets, ...

Dr Rudi Kuhn does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their ...

The worlds around our sun run the gamut from small and lifeless chunks of rock to gargantuan globes of gas. Our planet's siblings each have its own extreme features and crazy phenomena. -- Charles Q.

The History Channel has announced the launch of Planet H, a brand extension targeting kids ages seven to 11 with educational content about history. Developed by History and its parent company, A+E ...

It's past midnight in the dim telescope control room, but Dominique Naef's day has suddenly brightened. He twitches his computer cursor over a wavy line. "I like it," the Swiss astronomer says, ...