Feb 18, 2020 - Science

Cosmic rays change atmosphere of Saturn's moon, Titan

A photo of the outline of a planet.

Hazes above Titan's atmosphere. Photo: NASA/JPL-Caltech/SScI

Galactic cosmic rays from outside of the solar system may change the atmosphere of Saturn's moon Titan, according to a new study.

Why it matters: Titan is one of the most intriguing objects in the solar system — with a thick atmosphere and liquid lakes of hydrocarbons — and scientists think it could harbor the ingredients necessary to support life in some form.

What they found: The new study in the Astrophysical Journal reveals that certain molecules in Titan's atmosphere are likely broken apart by not only the Sun's ultraviolet light, but by cosmic rays as well.

  • This means that scientists may need to factor cosmic rays into models of how Titan's atmosphere came to look the way it does, potentially changing how we understand the world and even its habitability.
"Figuring all this out is a really big deal because it will teach us about how planets make organic chemicals in their atmosphere. ... Maybe we could learn about what types of organics (potential life building blocks and food!) got made on early Earth or are being made on other worlds beyond our Solar System."
— Michael Malaska, a researcher unaffiliated with the study, to Axios via email

Yes, but: It's still not a sure thing that cosmic rays are having this effect on molecules in Titan's atmosphere, and new data is needed to confirm the finding.

The big picture: Titan will get a close-up mission of its own when NASA's Dragonfly launches in 2026.

  • The mission will use a drone to fly to various points of interest on Titan's surface, hunting for signs of life and characterizing the moon's atmosphere from within.
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