NASA Discovers Vital Organic Molecule on Titan
Titan might be just one of dozens of Saturnian moons, but it’s one of the most fascinating objects in the solar system regardless. Astronomers often refer to Titan as a planet-like moon — it’s larger than Mercury and has a thick atmosphere like Earth and Venus. The environment is not hospitable to human life, but scientists have still found numerous intriguing organic compounds. In the latest analysis, researchers from NASA have identified an important, highly reactive organic molecule in Titan’s atmosphere. Its presence suggests the moon could support chemical processes that we usually associate with life.
A thick organonitrogen haze obscures the surface of Titan, but scientists were shocked to see how varied and planet-like it was under all the clouds. Titan is the only object in the solar system aside from Earth that has permanent bodies of liquid on the surface. On Earth, the liquid is water, but the seas on Titan are composed of liquid hydrocarbons. However, just because humans wouldn’t be at home on Titan doesn’t mean the moon is completely uninhabitable.
The NASA team used the Atacama Large Millimeter/submillimeter Array (ALMA) to probe Titan’s murky atmosphere to better understand its complex chemical composition, and the researchers spotted a molecule known as cyclopropenylidene (C3H2). The team says this discovery has the potential to open up new arms of chemistry on Titan, many of them associated with life. Cyclopropenylidene is what’s known as a cyclic or “closed-loop” molecule similar to benzene, and for the record, scientists have known benzene exists on Titan since 2003. Cyclic molecules are a vital piece of organic chemistry and might even be precursors to life.
Titan isn’t the only place we’ve found cyclopropenylidene — it’s also a common constituent of molecular clouds drifting through space. However, this is the first time it’s been detected in an atmosphere. The molecules floating in space are too cold and far apart to facilitate chemical reactions, but on Titan, cyclopropenylidene could form molecules very much like the nucleobases of DNA.
The more we learn about Titan, the more fascinating its chemistry becomes. We may be looking at a mixture of molecules not unlike those that gave rise to life on Earth. Unfortunately, it’s hard to study Titan from so far away. NASA hopes to launch a mission to Titan in the late 2020s that can explore these questions in detail. The Dragonfly lander should arrive on Titan in 2034, based on current projections. This drone will fly between multiple sites on the surface, using its instruments to probe the moon for compounds of scientific interest.