Molecule thought to be building block for life detected off Earth for first time ever


According to, Astronomers have detected cyclopropenylidene (C3H2) in the atmosphere of Saturn’s moon, Titan. This molecule is an extremely rare hydrocarbon that has, until now, existed only on Earth in laboratories.

This extremely rare molecule reacts easily with other molecules to form compounds, so it is thought by scientists to be a building block for more complex organic molecules that could one day lead to life. “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 astrobiologist Melissa Trainer of NASA’s Goddard Space Flight Center, one of the chief scientists in NASA’s upcoming Dragonfly mission set to launch in 2027, sending a probe to Titan to study its prebiotic chemistry.

This molecule is so rare that it has never been detected before in any atmosphere of any investigated planet, in our solar system, or elsewhere. The only other place it can remain stable is in the cold void of interstellar space. Cyclopropenylidene has been described by NASA researchers as a “very weird little molecule” which doesn’t tend to last long in atmospheric conditions because it reacts very quickly and easily with other molecules to form compounds.

“We’ll be looking for bigger molecules than 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 on the surface,” said Trainer. A geologist at NASA’s Jet Propulsion Laboratory, Rosaly Lopes, who is also studying Titan, has said, “We’re trying to figure out if Titan is habitable… 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.”

Titan is a very interesting place to study, with its hydrocarbon lakes and clouds, and its predominantly nitrogen atmosphere, which is four times thicker than Earth’s. Scientists also believe that under its surface lies a huge ocean of salt-water, with water as salty as the saltiest ocean on earth, the Dead Sea. This discovery of Cyclopropenylidene increases the chances of finding complex organic molecules, furthermore increasing the anticipation of NASA’s Dragonfly mission.



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