Its cold banks may be embedded with strange minerals that are not found on Earth.
The cold shores of the lakes of the moon Titan of Saturn is one of the points in our solar system that most attracts the attention of scientists, but is still surrounded by mysteries. Now a new study indicates that they may be embedded in strange minerals that are not found on Earth, including a rare solid acetylene and butane co-crystal.
Acetylene and butane exist on Earth as gases and are commonly used for welding and fuel stoves. On Titan, with its extremely cold temperatures, acetylene and butane are solids and combine to form crystals.
The new mineral could be responsible for the ‘rings bathtub’ suspected there around the hydrocarbon lakes on Titan, according to Morgan Cable’s Jet Propulsion Laboratory of NASA in the Institute of Technology California, who presented the new research at the Astrobiology Science Conference of 2019.
The lakes of Titan are full of liquid hydrocarbons. Previous research on images and data collected during the Cassini mission has shown that lakes in the dry regions of the moon near the equator contain signs of evaporated material, such as rings in a bathtub.
To create conditions similar to Titan’s in the laboratory, the researchers started with a custom-made cryostat, a device to keep things cool. They filled it with liquid nitrogen to lower the temperature and then heated the chamber slightly, so that the nitrogen became gas, which is mainly what the atmosphere of Titan contains.
Then, they released what abounds in Titan, methane and ethane, as well as other molecules that contain carbon, and looked for what was formed. The first things that left their hydrocarbon soup on Titan were the benzene crystals.
Benzene is perhaps best known as a component of gasoline and is a snowflake-shaped molecule made from a hexagonal ring of carbon atoms. But Titan’s benzene was a surprise: the molecules rearranged and allowed the ethane molecules to enter, creating a co-crystal.
Then, researchers discovered the acetylene-butane co-crystal, which is probably much more common on Titan than in benzene crystals, based on what is known about the composition of the moon, Cable said.
In the cold climate of the moon, the acetylene-butane co-crystals could form rings around the moon’s lakes as the liquid hydrocarbons evaporate and the minerals disappear, in the same way that the salts can crust over the edges of the lakes and seas of the Earth, according to Cable.
To confirm if Titan has cockpit rings of co-crystals and other undiscovered hydrocarbon crystals, scientists will have to wait until a spacecraft can visit the coasts of this moon, Cable said. “We still do not know if we have these bathtub rings,” he said, and concluded: “It’s hard to see through the hazy atmosphere of Titan.”