The outer solar system was once thought to be not much more than a frozen wasteland, at least in terms of the many moons orbiting the gas and ice giant planets. But with the intriguing discoveries made by robotic probes such as Voyager, Galileo and Cassini, we now know differently.
Not all that long ago, it was considered very unlikely that life could exist anywhere else in the solar system, apart from maybe Mars. A variety of robotic spacecraft missions, however, have changed scientists’ views; there are indeed a handful of other worlds in our own cosmic backyard which it is now known could potentially be habitable after all.
Europa is a fascinating little world, a moon with an icy crust and a subsurface global ocean. The environment is similar to the ice-covered waters at the Earth’s poles. Now scientists think that there may be another feature which is also found on Earth – huge frozen spikes of ice on the surface.
When Pluto was first discovered, it wasn’t known if it had any moons, and it was already a tiny world itself, smaller than Mercury (which doesn’t have any moons). As of last year however, five moons have been found orbiting Pluto! Now a new study announced today suggests that there may be up to ten more little moons or moonlets keeping Pluto company in the outer fringes of the solar system.
Until relatively recently, it was thought that the best, or perhaps only, place to look for life elsewhere in the solar system was Mars. The other inner planets were much too hot while the outer gas and ice giants were far too cold – the chances of any kind of life being found, even microbes, was considered extremely unlikely at best.
It might seem that way in this new photo released on November 5, 2012, taken by the orbiting Cassini spacecraft, but this is actually the tiny moon Methone. The oblong shape and smooth surface make Methone look more like a huge egg than a moon.