Titan’s strange chemical world is simulated in microtubes


The scenery Titan, Saturn’s largest moon, is both familiar and super unfamiliar. Like the earth, Titan also has rivers, lakes, clouds and falling raindrops, as well as icebergs and a thick atmosphere. But Titan’s chemical cycle is not water, but is composed of liquid methane, which is an organic molecule composed of one carbon and four hydrogen atoms. Researchers believe that this swirling mixture of methane, coupled with the moon’s nitrogen-rich atmosphere, surface water ice, and some energy from volcanic or meteor impacts, may be the perfect formula to create some simple life form.This is why Titan, like Jupiter, is one of the potential hot spots for life in the solar system Ice Moon Europa.

Several expeditions are preparing to launch into these distant worlds in the next ten years: European mission to Europa In 2022, NASA’s Europa Clippers In 2024, the innovative NASA Dragonfly helicopter Go to Titan in 2027.

But before these spacecraft leave, scientists want to understand how the planetary chemistry on these satellites works. Now, a researcher has reconstructed the Titan’s environment in a small glass cylinder and mixed organic chemicals under the same temperature and pressure conditions as the satellite.Liquid organic molecules on the earth-such as methane and benzene-become solid ice mineral crystals on Titan because it is too cold, sometimes as low as -290 degrees Fahrenheit, according to Tomche Lenchevsky, Assistant Professor of Chemistry at Southern Methodist University, and the lead researcher of the experiment gave a speech at the American Chemical Society meeting this week.

In a series of experiments, Runčevski took out a small glass tube, sucked out the air in it with a pump, and added water ice. Then, one at a time, he added nitrogen, methane, its chemically related ethane and other organic compounds. Each time, he would change the composition of the chemical mixture in the glass cylinder to see what would happen. Next, he applied pressure-about 1.45 times the pressure of the earth’s atmosphere-and lowered the temperature by surrounding the vial with extremely cold air.

“We introduced a series of chemicals, just as they were introduced to Titan,” Runčevski said. “First we will put [the glass tube] Remove all oxygen in a vacuum, and then we put in methane to simulate the atmosphere on Titan. Then we put in other organic molecules and conduct research. “

Under the atmospheric pressure and temperature of the moon, he discovered that two organic molecules on Titan that are toxic to humans on Earth-acetonitrile and propionitrile-became a single crystalline form. On Titan, these two molecules are formed by combining nitrogen and methane, plus energy from the sun, Saturn’s magnetic field, and cosmic rays. Acetonitrile and propionitrile initially existed in the atmosphere as gases, then condensed into aerosols, and then landed on the surface of the moon, turning into various forms of solid mineral blocks.

I understand whether you have reached a chemical overload.But if you care about biology, or more accurately Exobiology, science Life exist other planet, The shape and form of the compound are very important. Under the conditions on Titan, these two chemicals were combined into a crystal shape on Earth for the first time.

Another important finding is that the outer surface of the crystal also has a slight charge or polarity on its surface. This surface charge can attract other molecules, such as water-which is essential for forming the building blocks of carbon-based life.

This new experiment does not prove the existence of life on Titan, but it means that researchers can discover new things about the strange, cold surface environment of the NASA Dragonfly spacecraft even before it landed there. “We can’t say that there is or no life on Titan, but we can say with certainty that there is a condition for life,” Runčevski said. “Titan is the closest thing to earth, and it can breed life in a way that we think is similar to life on earth.”


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