'Weird' Molecule Detected on Titan Has Never Been Found in Any Atmosphere

 Titan, the already pretty weird moon of Saturn, just got a touch bit weirder. Astronomers have detected Cyclopropenylidene (C3H2) in its atmosphere - a particularly rare carbon-based molecule that's so reactive, it can only exist on Earth in laboratory conditions.

In fact, it is so rare that it's never before been detected in an environment, within the system, or elsewhere. the sole another place it can remain stable is that the cold innocent of the part. But it's going to be a building block for more complex organic molecules that would someday cause life.

"We think about Titan as a real-life laboratory where we are able to see similar chemistry thereto of ancient Earth when life was control here," said astrobiologist Melissa Trainer of NASA's Goddard Space Flight Center, one in every one of the chief scientists set to research the moon within the upcoming Dragonfly mission launching in 2027.

"We'll be trying to find bigger molecules than C3H2, but we want to grasp what's happening within the atmosphere to know the chemical reactions that lead complex organic molecules to create and precipitate to the surface."

Cyclopropenylidene – which even NASA researchers describe as a "very weird little molecule" – doesn't tend to last long in atmospheric conditions, because it reacts very quickly and simply with other molecules, forming other compounds.

Once it does so, it's not Cyclopropenylidene. In the region, any gas or dust is typically very cold, and really diffuse, which suggests compounds aren't interacting much, and Cyclopropenylidene can lallygag around.

Titan is incredibly different from the part. It's a variety of soggy, with hydrocarbon lakes, hydrocarbon clouds, and a predominantly nitrogen atmosphere, with a small amount of methane. The atmosphere is fourfold thicker than Earth's atmosphere (which is additionally dominated by nitrogen). Under the surface, scientists think there is a huge ocean of saltwater.

In 2016, a team led by planetary scientist Conor Nixon of NASA's Goddard Space Flight Centre used the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile to probe the moon's atmosphere, searching for organic molecules.

It was within the tenuous upper atmosphere, high above the surface, where they detected an unknown chemical signature. By comparing it to a database of chemical profiles, the team identified the molecule as Cyclopropenylidene. It's likely that the thinness of the atmosphere at that altitude contributes to the molecule's survival, but why it appears on Titan and no other world may be a mystery.

"When I realized i used to be observing Cyclopropenylidene, my first thought was, 'Well, this can be really unexpected,'" Nixon said. "Titan is exclusive in our scheme. it's proved to be a treasure trove of recent molecules."

Cyclopropenylidene is of particular interest because it's what's called a hoop molecule; its three carbon atoms are linked together during a ring (well, a triangle, but the principle is that the same). Although Cyclopropenylidene itself isn't known to play a biological role, the nucleobases of DNA and RNA are supported by such molecular rings.

"The cyclic nature of the release this extra branch of chemistry that enables you to make these biologically important molecules," said astrobiologist Alexander Thelen of NASA's Goddard Space Flight Centre.

The smaller the molecule, the more potential it's - reactions involving smaller molecules with fewer bonds are expected to happen faster than reactions involving larger, more complicated molecules. which means reactions involving smaller molecules, purely through numbers, are expected to end in a more diverse range of outcomes.

Previously, benzene (C6H6) was thought to be the tiniest hydrocarbon ring molecule found in any atmosphere (including Titan's). Cyclopropenylidene has it beat.

Titan is already a hive of organic chemical activity. The nitrogen and methane split within the sunlight, triggering a cascade of chemical reactions. Whether those reactions could end in life could be a question scientists are dying to answer.

"We're trying to work out if Titan is habitable," said geologist Rosaly Lopes of NASA's reaction propulsion Laboratory. "So we wish to grasp 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 predict the ocean is where the habitable conditions are."

Working out which compounds are present within the atmosphere could be an important step in this research process. Cyclopropenylidene could also be small, and strange, but this extremely rare molecule can be a key piece of the Titan chemistry puzzle. Now we just need to determine how it fits in.