17 julio 2013

A liquid lake on Saturn’s moon

A false-color mosaic of Ligeia Mare – the second-largest known body of liquid on Saturn’s largest moon, Titan. It’s larger than Lake Superior on Earth.

Ligeia Mare, a lake on Saturn’s moon Titan, in a false-color image from NASA’s Cassini spacecraft. Image v8a NASA/JPL-Caltech/ASI/Cornell

Ligeia Mare is one of the many bodies of liquid in and around the north polar region of Saturn’s largest moon, Titan. The lake is liquid, but the liquid isn’t water, which would freeze at Saturn’s distance from the sun. The temperature at Titan’s surface is about -289 degrees Fahrenheit (-178 degrees Celsius). Instead, the liquid in this Titan lake is mainly methane and ethane as well as other liquid hydrocarbons. The lake’s name comes from one of the beautiful and dangerous sirens in Greek mythology, Ligeia. The sirens were said to sing so sweetly that passing sailors would shipwreck on the rocky coast of their island. Ligeia Mare is second in size only to another lake, Kraken Mare, on Titan. It measures approximately 260 miles by 217 miles (420 km by 350 km) and has a shoreline that’s longer than 1,240 miles (2,000 km)! A day at the beach, anyone?

This image of Saturn’s largest moon Titan is from Cassini – taken in 2005. It shows approximately what Titan would look like to the human eye: a hazy orange globe surrounded by a tenuous, bluish haze. Titan has a very thick atmosphere that the eye can’t penetrate. The lakes on Titan are detected via Cassini’s radar.

The images on this page are just two of many amazing ones from NASA’s Cassini mission to Saturn. The spacecraft has been orbiting in and among Saturn’s rings and moons since 2004.

source and credit a earthsky