Photo: Cassini Imaging Team, SSI, JPL, ESA, NASA
Since the beginning of the 21st century, astronomers have made many discoveries in our solar system. With powerful telescopes, they were able to detect numerous, previously unknown moons on planets. In the meantime, researchers know more than 260 moons, most of them buzzing around Jupiter and Saturn - 53 each plus a few more that are not yet securely identified. On and below the surface of many of these moons other conditions prevail than on our earth's moon . Some boil downright, others are icy satellites - or both: The Saturn moon Enceladus is cold on the outside and has deep in its interior an ocean of almost boiling water.