Will A Proposed Mission To Saturn’s Moon Titan Find Life?

Is there life on Titan? Experts believe that the orange skies, icy dunes, and methane clouds on Saturn’s moon Titan might have enough in common with Earth that it’s worth exploring to see if life is or was present

In 2017, the Cassini-Huygens mission ended. Cassini orbited Saturn while Huygenslanded on the surface of Titan. Both of these crafts contributed to most of what we know about Titan today. It confirmed that Titan has water and a lot of reserves of carbon-containing chemicals. That’s exciting news because life on our planet is based on complex carbon-based substances, such as DNA.

It’s possible that water and carbon-containing chemicals combined in a primordial soup are the ingredients needed for life. So now, Dragonfly is a newly proposed mission to explore Titan’s surface via a lander that would be outfitted with helicopter-like propellers. Dragonfly’s mission could help experts learn more about how we evolved here on Earth, as well as possibly finding alien life.

Titan has some features similar to Earth. For instance, there are clouds and lakes (except they are filled with oil and not water) and even tides. Titan’s surface experiences storms just like we do on Earth except Titan’s storms are composed of methane and not water vapour. Furthermore, Titan’s temperature is well above absolute zero, but it’s not close to warm! The average surface temperature is minus 290 degrees Fahrenheit. Due to Titan’s dense atmosphere, one wouldn’t need a pressurized space suit to walk around, but one would need oxygen and a way to stay warm.

Although no one knows if life exists on Titan yet the Cassini-Huygens craft discovered a buried saltwater ocean, which was a good sign for primordial soup, this ocean sits approximately 65 kilometres below the surface of Titan, which is six times deeper than the deepest point of the Mariana Trench, the lowest spot on our planet.

Moreover, the mission discovered proof that suggests cryovolcanoes, which are volcanoes that burp ice instead of lava, might be the missing connection between Titan’s buried ocean and surface. Water pushed out from an erupting cryovolcano could combine with complex carbons on Titan’s surface. Scientists have already proven that similar interactions could generate amino acids, which are vital to life as we know it. Nevertheless, they need to take a closer to validate if cryovolcanoes exist and to look for other routes where water could reach the surface. Cassini only managed to take photos of suspected cryovolcanoes and Huygens didn’t land close to one.

But with the Dragonfly mission, scientists could explore sites where cryovolcanoes might be. Dragonfly would look for remnants of ice deposited on the surface by cryovolcanic eruptions.

This labeled graphic illustrates how different organic compounds make their way to the seas and lakes on Titan, the largest moon of Saturn. Credit: ESA

What’s more, various sources of carbon, the other ingredient needed for an excellent primordial soup, is found on Titan’s surface.

One source is the simple carbon-based chemical methane. Methane makes up a significant fraction of Titan’s atmosphere, which results in a thick haze. Cassini-Huygens also found Titan’s lakes are primarily filled with methane. Titan has a methane cycle, much like Earth’s water cycle: oily methane rain fills Titan’s lakes, and evaporation creates thick methane clouds. Cassini also managed to capture photos of dried river channels, which could move methane on the surface.

However, Titan’s methane haze is mysterious because it actually shouldn’t be there. Evaporation from Titan’s surface isn’t enough to restore the methane in the atmosphere, which is continually being subjected to reactions that make it form other chemicals. The amount of methane found in Titan’s haze should have been eliminated millions of years ago.

Fortunately, the mobility of the proposed Dragonfly mission would give it a significant advantage over Cassini-Huygens when it comes to the search for methane. Dragonfly could find cryovolcanoes, and it could also look for deeper deposits of carbon and signs of methane-producing life. Thus, if the right ingredients for primordial soup exist on Titan to produce life, Dragonfly has a good chance of finding it.

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