Weird Molecule Found On Titan Has Never Been Seen Before In An Atmosphere

The biggest moon of Saturn, Titan, is an icy world whose surface is completely obscured by a golden hazy atmosphere. Titan is the second biggest moon in our solar system. Only the Ganymede Moon of Jupiter is larger, by just 2%. Titan is larger than the Earth's moon and larger than Mercury's planet.

A strange molecule has been found in the atmosphere of one of the moons of Saturn, Titan. NASA scientists found a peculiar compound called cyclopropenylidene (C3H2) in its atmosphere-an extremely rare carbon-based molecule that is so reactive that it can only exist on Earth under laboratory conditions.

According to the astronomer, cyclopropenylidene (C3H2) has never been detected in any other atmosphere. Indeed many chemists have probably barely heard of it or know how to pronounce it: cyclopropenylidene, or C3H2. Benzene is the only other cyclic molecule to be found in Titan’s atmosphere so far, and was previously considered to be the smallest unit of ringed hydrocarbon molecules found in any atmosphere. Scientists say that this simple carbon-based molecule can be a precursor to more complex compounds that could form or feed Titan's life.

Cyclopropenylidene is also a "cyclic" or closed-loop molecule; Closed-loop molecules like this are important because they form the backbone rings for the DNA nucleobases, the complex chemical structure that carries the genetic code of life, and the RNA, another critical compound for the functions of life.

Scientists first noticed the molecule, which consists of three carbon atoms and two hydrogen atoms, while sifting through the light signatures collected by the Atacama Large Millimeter/Submillimeter Array (ALMA) in northern Chile.

Although the substance has been found in many other areas throughout the galaxy, it has never been found in the atmosphere before. This is because the substance reacts so easily with other molecules; previously, it was found only in clouds of gas and dust floating between star systems—in other words, regions that are too cold and diffuse to facilitate many chemical reactions.

"We think of Titan as a real-life laboratory where we can see similar chemistry to that of ancient Earth when life was taking hold here," said Melissa Trainer, a NASA Goddard astrobiologist. Trainer also said "We'll be looking for bigger molecules than cyclopropenylidene (C3H2),", "but we need to know what’s happening in the atmosphere to understand the chemical reactions that lead complex organic molecules to form and rain down to the surface.

Titan is a hub of organic chemical activity, and quite different from interstellar space. It's kind of soggy, with hydrocarbon lakes, hydrocarbon clouds, and a mostly nitrogen atmosphere, with a bit of methane. The atmosphere is four times thicker than the Earth's atmosphere. Under the surface, scientists believe there is a vast ocean of saltwater.

"We're trying to figure out if Titan is habitable," said Rosaly Lopes, a senior research scientist and Titan expert at NASA's Jet Propulsion Laboratory (JPL). "So we want to know what compounds from the atmosphere get to the surface, and then, whether that material can get through the ice crust to the ocean below, because we think the ocean is where the habitable conditions are."

 Michael Malaska (JPL planetary scientist) said, "It's a very weird little molecule, so it's not going be the kind you learn about in high school chemistry or even undergraduate chemistry." Malaska also added, finding molecules like C3H2 is really important in seeing the big picture of Titan: "Every little piece and part you can discover can help you put together the huge puzzle of all the things going on there."