Artist’s impression of ancient effects on Saturn moon Titan
Alamy Science / Image Photo Library
By Jonathan O’Callaghan
Saturn’s frigid moon Titan has long been involving scientists in finding life in the Solar System. Its surface is covered in organic hydrocarbons, and its frozen crust is thought to cover an ocean of water. Theoretically an asteroid or comet entering the moon could be a combination of these two ingredients, according to a new study, with the resulting effector shadows giving them a unique place to start life.
The idea is “very interesting,” says Léa Bonnefoy, a planetary scientist and Titan scientist at the University of Paris. “If you have a lot of melt water creating a temporary warm pool on the surface, you can have conditions that would be favorable for life,” she says. And, “Having organic material cycling from the surface into the ocean makes the ocean a little more arable. ”
Scientists have believed that an ocean sits about 100 kilometers below Titan’s crust ever since 2012, when NASA’s Cassini mission measured changes in the full moon. Alvaro Penteado Crosg, a planetary geologist at the University of Campinas, knew that the moon was full of many great effects. He wondered if any of the effects were big enough to break the bark and weld the surface organic matter with the water below. Maybe that turned out to be “a primordial soup you need to improve your life,” says Penteado Crighinn.
To find out, he and his colleagues modeled the impact for the largest crater on the moon, Menrva 425-kilometers wide, which is thought to have been created 1 billion years ago. The model suggested that the crater was the result of a 34-kilometer-wide space rock hitting the surface at 7 kilometers per second.
The impact on Menrva, Titan’s largest crack, may have been to control the moon’s frozen crust.
NASA
The heat would have the effect of creating a lake in the crater, according to the model, which the team presented this week at the Lunar and Planetary Science Conference. The lake would probably have existed only for 1 million years before it froze in the freezing temperatures of Titan. But Penteado Crigear says this may be enough time for microorganisms to emerge, taking advantage of melt water, organic molecules, and heat from the impact. “That’s great for bacteria.”
While the team’s research focused on Menrva, Penteado Crigear says it is possible that smaller impacts were enough to break through Titan’s ice shell, perhaps even at Selk’s – a 90-kilometer-wide crack of about 5000 kilometers. away. Selk is thought to be much younger than Menrva, perhaps just a few hundred million years old, which would mean that there would be no evidence of a newer life. “Selk may have a better chance of storing some fossil bacteria in the ice,” says Penteado Crighinn.
Selk is the planned landing site for NASA’s Dragonfly mission, a $ 1 billion self-powered and nuclear-powered drone launched in 2027 and reaching Titan 2036. If the impact breaking the ice crust here, the mission might find out.
But Elizabeth Turtle, principal investigator for the Dragonfly mission at Johns Hopkins University ‘s applied physics laboratory, is less certain. “There is no strong evidence that you were puncturing,” she says.
However, Dragonfly could visit other craters in an extended mission. And while Menrva may be too far away, it could be an interesting landing site in the future, Penteado Crighinn says.