The icy moon of Saturn Titan is like a twin alternate reality of Earth with its. It is the only other world in our solar system dominated by organic molecules and decorated with lakes and rivers. It even has a dense atmosphere, seasonal climate and rainfall.
Even if it’s not exactly the same as our house – its lakes are filled with methane and the rain would probably burn our skin –has proven to be a promising arena to search for signs of alien life.
NASA intends to launch a rotorcraft, which they describe as a “big drone”, at Titan in 2027 with the, in the hope of locating something remarkable. But because it would take another seven years for the NASA craft to reach the planetary body – it is nearly a billion kilometers away – many researchers are struggling to understand Titan’s environment here on Earth. .
A new experiment, conducted by researchers at Southern Methodist University, aimed to do this by mimicking Titan conditions in a test tube. Titan looks alien, but it shares many organic molecules with our planet. But it’s a much colder place.
“If we want to study the minerals on Titan, we have to take a look at these common organic molecules… but look at them through different eyes; look at them through the prism of Titan, ”says Tomče Runčevski, an assistant professor at Southern Methodist University and principal investigator of the experiment present at the American Chemical Society Fall Meeting.
Runčevski’s “Titan-in-a-glass” aimed to do just that. The team combined Titan’s characteristics, such as its plunging temperatures and characteristic liquids, into glass cylinders. Then they added two molecules, acetonitrile and propionitrile, found in the lunar atmosphere.
On Titan, these compounds come in the form of solid crystals that contain sequences of “polymorphs”, or changes in structure, that depend on temperature. The chemical makeup is the same, but the way the chemicals bind is slightly different depending on heat or cold.
Mixing the molecules together produced a somewhat surprising result.
When the researchers conducted their “Titan-in-a-glass” experiment, the structural sequences of these two molecules changed, with the high and low temperature polymorphs stabilizing. The properties of the compounds have also been adjusted.
“This is very interesting and important, because so far … all the studies that have been done for acetonitrile – and there are a lot of studies – assume that they will have the polymorph at low temperature, because on Titan, the temperature is low. “
Titan displays freezing temperatures as low as -290 degrees Fahrenheit. But this did not prevent the formation of polymorphs at high temperature. The result shows that it’s not just the temperature that affects Titan’s chemistry.
“On Titan, we cannot assume that these molecules will be alone,” Runčevski said. “Titan is a world – the chances that we can meet these molecules in the form that we propose, it will be decent.”
Surprisingly, the new properties of acetonitrile and propionitrile can also answer many long-standing questions in earth chemistry.
“On Earth, these chemicals are liquid, so no one cares what their solid might look like. And now, thanks to Titan, this type of research has been revitalized and people have started to look at these fundamental questions again. “, remarked Runčevski.
Adding this, “The fact that today – in the 21st century – we are still discovering things about organic solvents and the most common fuels on Earth is fascinating.”
The team aims to compare their results to spectroscopic data collected by NASA Cassini-Huygens mission, which sent a probe around Saturn and its moons between 1997 and 2017.