Space Exporation: Titan’s Hydrocarbon Lakes


Imagine being submersed in a lake of liquid methane.

If you’re still reading then obviously you’re curious. Scientists may be close to sending a floating probe to the lakes of hydrocarbons on Titan’s surface. One small, but important constituent in the moon’s atmosphere and on the surface, is methane. Methane gas is not uncommon on earth, ask my old roommate. But conditions for liquid methane are down right bizarre compared to any known conditions here on earth.

Saturn’s largest moon, Titan is a world of mostly nitrogen and small amounts of methane in its atmosphere, not too dissimilar to earth. A satellite image of Titan in the visible wavelengths, however, is just a beautiful homogenous yellow haze. So we must probe the small world with infrared light, longer than our visible red light, to observe the surface features.


Even more fascinating, Titan has a precipitation cycle just as Earth has the water cycle. Methane can exist in two of the three phases on Titan, liquid and vapor, but researchers have recently come across data that might suggest hydrocarbon (methane and ethane) ice as well. That’s pretty spectacular if you ask me.


A joint mission of NASA and ESA, the Cassini satellite deployed the Huygens probe which descended through the atmosphere of Titan and settled on the surface before losing contact. All through its journey, the probe was able to not only take and transmit vital atmospheric and chemical data, but also images.

One of the largest topics in space exploration is for life, understandably so. Aside from ethical dilemmas, exploring Jupiter’s moon Europa might be a better target than Titan. Europa has liquid and solid water, why not focus on this world instead? For one, an international team of experts could not fully agree 100% on a way to probe Europa without contaminating potential life. So in the mean time, maybe we can explore somewhere that have conditions extreme enough to handle our potential contamination, but also have environments that are similar to when life on earth was prebiotic. Mmmm, how about Titan?

Christophe Sotin of the Jet Propulsion Lab,”Dynamic, methane-driven photochemistry at Titan produces prebiotic molecules similar to those that must have existed on an early Earth. Though it may be shorter-lived than previously believed, details about Titan’s methane cycle provide a glimpse into the kinds of conditions that existed on our planet before life evolved.”

Which brings us back to submerging in liquid methane/ethane. The two main objectives I can propose from these articles are: this could be a very good step towards the approach of Europa and this could broaden our concept of our own origins as well as any potential new forms.

Jeremy Hsu,”a Titan mission may also prove less technically challenging than the unprecedented step of putting landers or submersible drones on Jupiter’s icy moon of Europa.”

Chemist Dr. Chao He on the environments on Titan,”The study of organic chemistry on Titan’s surface would extend our understanding of the diversity of prebiotic chemistry, and perhaps life’s origin on Earth.”

If we plan on trying to figure out life, any type of life, knowing the origins of ours is vital since it’s the only concrete form we know. And finding conditions similar to any stage of life on earth in present day surroundings, well that’s plain fascinating.

One thing that seemed to be void in all the articles was budget justification for a layperson. Unfortunately our world has numerous issues that are of extreme importance in which this money could possibly help. Even as an undergrad who is just interested in this topic, I have been asked numerous times, “Why are we focusing so much time and resources into exploring space?” “Don’t you think there are more important issues at hand on earth?”

No answer I have been able to give, no matter how relevant to me, seems to fully drive a convincing answer to the questioner. As an aspiring scientist, I almost never think about having to justify any exploration, but I haven’t dealt with the real world yet either, I guess.

In addition, the work that I am doing with Titan seems to follow the overall topic in two of these papers: decreasing methane and the original source of methane. The later could be a by-product of living organisms. The work of Eliot Young of Southwest Research Institute is the Principal Investigator for a project that aims to accurately determine if there are any current or near-past sources of methane on Titan. The report by Sotin appears, without a doubt, to ensure methane is on its way out on Titan.

Eliot Young, “Our observing program has been designed to address two ongoing questions: what is the composition of various surface units on Titan (including lakes, dunes, etc.) and is there a discernible source of atmospheric methane?”
NASA KECK 2013A PROPOSAL #80 Coordinated Image Cubes of Titan during the T90 Cassini Flyby

Life on Titan:

Pictures from Huygens lander:
Cassini Science League