T itan, which is 50% bigger than our own Moon, was the subject of the Huygens probe in 2004, glimpsed at the end of this clip. It is the only known moon with a substantial atmosphere (of molecular nitrogen, as on Earth), but it is far, far colder than even our Antarctica, at -180 degrees Celsius. Its surface is primarily rock and water ice - and it is the only world aside from Earth on which stable bodies of liquid have been seen. But these are not lakes of water, which freezes as hard as rock on Titan. No, Titan's seas are made of methane.
Name: Galactic Core
Category: Galaxies, Stars & Nebulae