The Saturnine moon is one of the most interesting in the solar system

Mar 7, 2014 13:13 GMT  ·  By
Cassini allows astronomers a window into the internal structure and properties of Titan, Saturn's largest moon
   Cassini allows astronomers a window into the internal structure and properties of Titan, Saturn's largest moon

Officials with the NASA Jet Propulsion Laboratory (JPL) in Pasadena, California, are proud to announce that the Cassini spacecraft has on March 6 completed its 100th flyby of Saturn's largest moon, Titan. The probe has been studying the gas giant, its ring system, and its moons since achieving orbital insertion around Saturn, on July 1, 2004.

Just short of a decade has passed since then, but our understanding of Titan has progressed exponentially. When Cassini arrived at Saturn, all we knew about this peculiar moon was that it has a diameter roughly equal to that of Mercury, and that it appeared a fuzzy orange color when viewed through a telescope.

Spectrometers had also revealed that its thick atmosphere was mostly made up of nitrogen, however little data was available on what existed below this gas mass. Since Cassini started conducting flybys of Titan, little by little, these mysteries have been progressively cleared up, and a new understanding of this pseudo-Earth-analog world obtained.

The vast majority of data we now have on Titan, and other Saturnine moons as well, comes from the Cassini spacecraft. Yesterday, March 6, it again flew past Titan, this time at a distance of 1,500 kilometers (933 miles). This marked the spacecraft's 100th flyby of the moon and gave JPL researchers the chance to remember some of the most interesting discoveries the probe made over the last decade.

Undoubtedly the most interesting thing about this celestial body is that it shares a lot of things in common with our planet. What sets Earth apart from Titan are largely temperature levels and distance from the Sun, as well as the basic chemical makeup of both worlds. However, Titan features oceans, lakes, and rivers, an active atmosphere with rain and thunderstorms.

Such atmospheric phenomena are not available at such complex levels anywhere else in the solar system. What differentiates them from their counterparts on Earth is that they use, and revolve around, liquid hydrocarbons such as methane and ethane, instead of water. Other than that, the natural cycles are identical.

After analyzing these aspects in great detail, Cassini is now ready to move on to even more complex studies, such as for example determining the exact depth of the largest seas on Titan. “It's something we didn't think we could do before,” JPL Cassini scientist Michael Malaska explains.

The probe's “radar can measure the depth by receiving two different bounces: one from the surface and one from the bottom of the sea. This technique was used to determine that Ligeia Mare, the second largest sea on Titan, is about 160 meters [525 feet] deep,” he adds.

“When coupled with some laboratory experiments, it gives us information about the composition of the liquid in Ligeia Mare, too,” the expert goes on to say. Since Cassini is currently scheduled to remain around Saturn until at least 2017 – and most likely through 2020 – we are likely to gain even more data on Titan before the mission reaches its end.

“The astrobiological potential for Titan is two-fold. Could a unique form of methane-based life exist in Titan's liquid lakes and seas? With a global ocean of liquid water beneath its icy crust, could life exist in Titan's subsurface ocean?” concludes JPL Cassini investigator Linda Spilker.