Register for an account

X

Enter your name and email address below.

Your email address is used to log in and will not be shared or sold. Read our privacy policy.

X

Website access code

Enter your access code into the form field below.

If you are a Zinio, Nook, Kindle, Apple, or Google Play subscriber, you can enter your website access code to gain subscriber access. Your website access code is located in the upper right corner of the Table of Contents page of your digital edition.

The Sciences

37. Saturn's Moon Has a Hidden Ocean

Cassini's flybys reveal an icy secret on Saturn.

By Jason DaleyJanuary 10, 2013 6:00 AM
titan.jpg
Smog-covered Titan passes in front of Saturn's thin rings; their shadow makes stripes on the planet. | NASA/JPL-Caltech/Space Science Institute

Newsletter

Sign up for our email newsletter for the latest science news

Titan, the largest of Saturn's moons, is a remarkable place. Bigger than the planet Mercury, it has a thick, opaque atmosphere; complex weather; and lakes of liquid natural gas. Last June astronomers added another wild detail to the profile: a global ocean buried beneath the icy surface.

The discovery came from six flybys of Titan that NASA's Cassini spacecraft, orbiting Saturn since 2004, made between 2006 and 2011. During those passes, astronomers measured how the intense pull of Saturn’s gravity deforms Titan during its 16-day revolution around the ringed planet. If Titan were a solid body, it would barely be affected, bulging only about 3 feet during its closest approach to Saturn. Cassini's measurements revealed that Titan actually bulges a substantial 30 feet, indicating that the moon's surface rides on top of a sloshing layer of water of unknown depth. Scientists suspect that Jupiter's moons Europa and Ganymede also have hidden oceans. But Titan is particularly intriguing because it has abundant organic molecules on its surface. Organics and liquid water are crucial ingredients for life.

So far, Cassini's observations hint at a disappointingly cold and inhospitable ocean floor. A dedicated Titan probe could give a real answer. In an era of diminished budgets, though, that may not happen for many years.

2 Free Articles Left

Want it all? Get unlimited access when you subscribe.

Subscribe

Already a subscriber? Register or Log In

Want unlimited access?

Subscribe today and save 70%

Subscribe

Already a subscriber? Register or Log In