Jupiter's moon Europa and Saturn's moon Titan are both potential bearers of alien life. Now, a new study may strengthen the case for Titan.
A trove of data from NASA's Huygens and Cassini missions has helped scientists discover a chemical trail, which indicates that the Saturn moon may support alien life. In fact, prebiotic conditions may already exist there.
As Saturn's largest natural satellite, Titan possesses Earth-like terrain, such as seas, rivers and lakes. Instead of water, however, these bodies are filled with liquid methane and ethane.
The moon's dense atmosphere, which appears as a yellow haze, contains methane and nitrogen. And as soon as sunlight hits this toxic atmosphere, hydrogen cyanide is produced — a potential key chemical for prebiotic conditions.
Hydrogen cyanide is an organic chemical that can react with other molecules or with itself. When it does, it can form long chains known as polymers.
One of these polymers is known as polyimine, a flexible chemical that allows mobility even during at frigid conditions. Polyimine can also absorb the energy of the sun, and turn into a possible catalyst for life.
Martin Rahm, the study's lead author and a postdoc researcher in chemistry, says polyimine can exist as various structures and can accomplish incredible feats at low temperatures.
An Important Blueprint
Rahm says the findings of the paper is a starting point in searching for prebiotic chemistry in conditions distinct from Earth.
To understand the "blueprint" of early planetary life, Rahm says scientists must think outside Earth-based biology.
"We are used to our own conditions here on Earth," says Rahm.
Indeed, our scientific experience on Earth is set in ambient conditions and room temperature. But according to Rahm, Titan is an entirely "different beast."
For instance, while Titan and Earth both contain flowing liquids, the temperatures on Titan are very low and no liquid water exists. And if Titan is studied using our biological terms, scientists are definitely going to be at a dead end.
Rahm, who took the aid of Nobel Prize in Chemistry winner Roald Hoffmann for this research, believes scientists need to continue examining the potential traces of hydrogen cyanide to understand how the chemistry evolves over time.
Furthermore, Rahm believes that if future data could show that there is prebiotic chemistry in Titan, then it would be a major scientific breakthrough.
The findings of the paper, which only indicate the prerequisites for a different kind of life on the Saturn moon, is only the first step.
Details of the research are featured in the journal Proceedings of the National Academy of Sciences.