STRANGEST MOONS IN THE SOLAR SYSTEM
All but two of our Solar System’s planets have satellites of one sort or another. Earth’s own Moon, a beautiful but stark, dead world shaped by ancient volcanoes and countless impact craters, is undoubtedly the most familiar, but it’s far from being the most interesting.
Each of the outer Solar System’s giant planets is accompanied by a large retinue of satellites, many of which formed at the same time and from the same ice-rich material as the planets that host them. Although far from the Sun and starved of solar heat and light, they nevertheless show as much variety as the planets themselves.
Here All About Space takes a trip to visit some of the strangest and most exciting of these astonishing worlds. Some, such as Jupiter’s Callisto and Saturn’s Mimas, have been frozen solid for billions of years but bear extraordinary scars from exposure to bombardment from space. Others, such as Saturn’s shepherd moons Pan and Atlas and Neptune’s lonely Nereid, have been affected throughout their history by interactions with their neighbours.
Most excitingly, some of these exotic worlds have been heated by powerful tidal forces from their parent planets, triggering phases of violent activity like those which shaped Miranda, Uranus’ Frankenstein moon. In some cases these forces are still at work today, creating fascinating bodies such as Jupiter’s tortured Io and Saturn’s icy Enceladus, whose placid exterior may even hide the greatest secret in the Solar System: extraterrestrial life itself.
Giles Sparrow
Space science writer
The author of over 20 books on popular science, Giles holds a degree in astronomy and is an editor specialising in science and technology.
ENCELADUS THE RING BEARER
Mass: 1.1 x 1020 kg (2.4 x 1020 lbs) Diameter: 504km (313 miles) Parent planet: Saturn Discovered: 1789, William Herschel
Since NASA’s Cassini probe arrived at Saturn in 2004, the ringed planet’s small inner satellite, Enceladus, has become one of the most intensely studied and debated worlds in the entire Solar System. It owes its new-found fame to
