In a remarkable revelation, NASA astronomers have detected the presence of the molecule cyclopropenylidene within the atmospheric layers of a celestial body.
In fact, cyclopropenylidene is so scarce that many chemists have not even heard of it. It is an “exotic reactive” organic molecule, formed from carbon and hydrogen (C3H2). Due to its high reactivity with other molecules upon exposure under normal conditions, it has never been found in the atmospheres of previous celestial bodies. It only exists within peculiar dust and gas clouds drifting between stars, where extremely cold temperatures prevent chemical reactions involving C3H2.
However, in a recent report published in the Astronomical Journal on October 15th, NASA astronomers revealed that they have discovered C3H2 on the moon Titan – the largest natural satellite of Earth – based on radio observations from the Atacama Large Millimeter Array (ALMA) astronomical observatory located in the Atacama Desert in northern Chile.
The combination of telescopes at ALMA allows scientists to collect and sift through unique light signals from Titan, which can unveil the chemical composition of its atmosphere through the energy emitted or absorbed by its molecules.
Conor Nixon, the leader of the research team from NASA’s Goddard Space Flight Center, emphasized that finding cyclopropenylidene on the surface of Titan is “a truly surprising and inexplicable discovery,” as its dense atmosphere is conducive to chemical reactions.
.jpg)
Composite Image of Saturn’s Moon Titan Captured by the Cassini Spacecraft. Photo: NASA.
Titan has been described as the most Earth-like world ever discovered. It possesses clouds, rain, rivers, lakes, and even salty ocean bodies beneath its surface. The moon’s atmosphere is four times denser than Earth’s and primarily consists of nitrogen and methane.
When nitrogen and methane molecules are broken down by the intense sunlight on Titan, their constituent atoms form a complex network of organic chemistry, which has garnered the special attention of astronomers. NASA consistently places the largest moon of Earth at the top of its list for extraterrestrial life exploration.
“We are still trying to understand whether life could exist on Titan. We want to know which compounds are falling from the atmosphere to the surface and whether they could penetrate the icy crust to reach the salty ocean below, as oceans are where life is most likely to form,” shared Rosaly Lopes, a senior scientist at NASA’s Jet Propulsion Laboratory (JPL).
Cyclopropenylidene is the only closed-ring molecule, aside from benzene, found in Titan’s atmosphere to date. This molecular form is highly significant because it serves as a “backbone” for the nucleobases of DNA and RNA.
Discovering a new molecule like C3H2 will aid scientists in gaining a better understanding of the processes occurring on Titan. “Each small piece we uncover will be an essential puzzle piece to complete the bigger picture,” added planetary scientist Michael Malaska from JPL.