A neutron star is the densest object astronomers can observe directly, crushing half a million times Earth's mass into a sphere about 12 miles across, or similar in size to Manhattan Island, as shown ...

Astronomers studying extreme planetary systems have identified worlds so massive that they rival the smallest stars in size.

This illustration shows the average brown dwarf is much smaller than our sun and low mass stars and only slightly larger than the planet Jupiter. Disclaimer: AAAS and EurekAlert! are not responsible ...

Saturn has 83 known moons, the most of any planet in our Solar System. This size comparison video from MetaBallStudios lines them all up, with London as the background. The same YouTuber recently ...