Titan chemical trail suggests prebiotic conditions on Saturn moon

ITHACA, N.Y., July 6 (UPI) -- The trail of chemicals detected on Saturn's moon Titan suggests the sort of conditions that precede the emergence of life -- prebiotic conditions.

Water and oxygen wasn't always abundant on Earth. A unique chemical evolution enabled life on Earth. These biological systems reinforced certain chemical cycles, yielding the planet we know today.

Scientists are keen to understand the chemical keys to prebiotic conditions. Planetary scientists believe one of them is hydrogen cyanide. When sunlight hits the hazy yellow atmosphere of Titan, made up mostly of nitrogen and methane, a series of chemical reactions produce hydrogen cyanide.

Researchers believe prebiotic conditions don't have to look like the chemical palette that produced life on Earth. Titan looks much different than Earth, but that doesn't mean it can't offer habitable conditions -- or at least conditions that might foster a new type of life form.

"This paper is a starting point, as we are looking for prebiotic chemistry in conditions other than Earth's," said Martin Rahm, a postdoctoral researcher in chemistry at Cornell University, explained in a news release.

The key, Rahm believes, is thinking outside the biological box and rejecting the blue-green blueprint offered by Earth. Titan is cold, and its rivers and lakes are filled with liquid methane and ethane.

Researchers know hydrogen cyanide can react with itself or other molecules to form long polymer chains, one of which is polyimine. Polyimine is chemically flexible, highly mobile and active at very low temperatures.

Rahm suggests polyimine chains can absorb the sun's energy and could potentially facilitate the emergence of life.

Rahm is the lead author of a new paper of Titan's chemistry and prebiotic potential, published this week in the journal PNAS.

"We need to continue to examine this, to understand how the chemistry evolves over time. We see this as a preparation for further exploration," said Rahm. "If future observations could show there is prebiotic chemistry in a place like Titan, it would be a major breakthrough."