This Saturday, April 22, we’re going to be saying goodbye to one of the most intriguing places in our Solar System. This will be the last flyby of Titan performed by NASA’s Cassini spacecraft, and our last close-up view of Titan for the foreseeable future.
Titan is a fascinating world that may just be one of the best bets for finding life in our Solar System. It is the only place other than Earth with bodies of liquid on its surface, in the form of liquid hydrocarbons. It has an Earth-like climate cycle, recycling methane instead of carbon. And it may also have a habitable subsurface water ocean.
When Cassini first arrived at Saturn in 2004, we knew very little about Titan. Our previous glimpses had come from flybys of the Pioneer 11 spacecraft in 1979 and the Voyager 1 and 2 spacecraft in 1980 and 1981, but the moon’s surprisingly thick atmosphere meant we couldn’t actually see its surface. That all changed with Cassini. It sent a probe built by ESA called Huygens to the surface on January 14, 2005, and has continually observed it using radar images since.
“Before Cassini got there, Titan was the largest piece of unexplored territory in the Solar System,” Trina Ray from the Cassini team at NASA's Jet Propulsion Laboratory (JPL) in California told IFLScience. “And so just to see how Earth-like this body is, with dunes of material covering the equator, with lakes and mountains and rivers, it just has been an incredible discovery.”
We can see signs of lakes and rivers on Titan in radar images. NASA
This will be the 127th flyby of Titan, labelled T-126 – the difference in numbers is due to the first two flybys being turned into three (A, B, and C), and people didn’t want to change the names of T-3 onwards. This will not be the closest flyby of Titan, which was T-70 in 2010, called a super-go-low flyby when it skimmed 880 kilometers (547 miles) above the moon. But this final flyby will be just as important as the rest.
“All the flybys are important,” said Ray. “But this one is a little more special.”