Enceladus as seen by Cassini. Credit: NASA/JPL/Space Science Institute
Saturn’s moon Enceladus is a mysterious world. Measuring just 512km in diameter it should be a cold lifeless body, practically unchanged since its formation. Yet it isn’t. It’s very much alive. NASA’s Cassini spacecraft has shown that this remarkable moon’s surface has, in parts, been smoothed and altered in the geologically recent past. Images sent back by the probe show great fissures on its surface and, most spectacularly, vast plumes of icy material erupting from its southern hemisphere.
Now scientists studying Enceladus have come to some fascinating conclusions about what could lie beneath its icy crust. In a new article for Sky at Night Magazine I talk to the scientists working on the data from Cassini. I explore their findings which, incredibly, seem to point to a liquid ocean of water under the ice at Enceladus. The article also discusses the various mechanisms which could be creating the plumes. You can read the full story, “Enceladus: water world”, starting on page 68 of the May issue.
Here’s another one of those stunning planetary images that really stops you in your tracks. It’s just been released by the Cassini mission imaging team and shows Saturn (and a few of its moons) as seen by the Cassini spacecraft, just last month. The eery illumination of the rings is due to the very low angle at which sunlight is striking them, combined with sunlight reflected off Saturn’s cloud tops.
Make sure you click the image above to see a much bigger version, to explore it in all its glorious detail, including the subtle pastel coloured bands of Saturn’s upper atmosphere. To give you a sense of scale, Saturn’s diameter (at its equator) is around 120,500 km. So you could fit just over 9 Earths across its disc. For more information on the image and what it shows see the Cassini website here.