A simple but uncommon molecule known as cyclopropenylidene has been discovered in the atmosphere of Titan, Saturn’s largest moon. This is the first time such a molecule has been discovered in the atmosphere of a celestial body, but not the first time it has been seen in space.
NASA scientists report in The Astronomical Journal that a small amount of this molecule was detected in the higher regions of the moon’s atmosphere. This molecule is quite reactive, so it's unlikely to be found in the denser parts of Titan’s atmosphere. Before this, the molecule was only been seen in the vast, diffuse clouds of interstellar space.
“When I realized I was looking at cyclopropenylidene, my first thought was, ‘Well, this is really unexpected,’” lead author Conor Nixon, a planetary scientist at NASA’s Goddard Space Flight Center, said in a statement. “Titan is unique in our solar system. It has proved to be a treasure trove of new molecules.”
The observations were conducted with the Atacama Large Millimeter/submillimeter Array (ALMA). Titan is one of the most fascinating worlds in the Solar System and the only other place apart from Earth with flowing rivers and lakes. Unlike our planet, however, these rivers and lakes are comprised of liquid hydrocarbons, mostly methane and ethane.
Titan is a cold frigid world with a dense atmosphere rich in carbon-based compounds. Scientists believe that processes happening on Titan could give us insight into what the Earth used to be like at the beginning of the solar system or even clues to what alien life might be like. There is no certainty that life is possible on Titan but it is an intriguing possibility.
“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) in Pasadena, California. “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.”
NASA is preparing a mission to go back to Titan. Dragonfly, as it is known, is expected to launch in 2027 and will study the chemistry of the moon's surface.
