Saturn is a magnificent planet. Its rings make it appear spectacular and have been a topic for scientific studies. Scientists have been able to send four missions to Saturn so far. They are Pioneer 11, Voyager 1, Voyager 2, and Cassini. While the first three were flybys, the Cassini entered its orbit and explored the planet and its moons for 14 years until it was declared dead in 2017. Scientists have now claimed to solve a puzzle involving the planet’s moon Rhea. Rhea is one of the 82 known moons of the gas giant. When Cassini flew past Rhea, it detected a mysterious compound on its surface. The compound is said to be a chemical. The chemical is hydrazine. Hydrazine is a colorless volatile alkaline liquid. It is a fuel used by space agencies mostly in rockets.
When Cassini flew past the moons of the second-largest planet, it noticed sunlight bouncing off their surfaces. It examined the sunlight to understand what the compounds on their surfaces are made of. The probe saw a similar compound on Rhea and other moons. It was noticed that some compounds on their surface absorbed a portion of sunlight in the UV range. Scientists initially speculated it to be water ice. But they were puzzled for a long time and continued with their researches. Experts at the Planetary Science Institute observed how the light bounced off during experiments in laboratories. They noticed that it matched what the Cassini spacecraft spotted on Rhea. They said that the compound could be hydrazine and chlorine.
Experts believe that hydrazine can be formed during chemical reactions that are present on Rhea. But it is hard to believe chlorine could be produced on the icy moon’s surface. According to NASA, the Cassini spacecraft used hydrazine as fuel for its thrusters. It was also speculated that the compound came from Cassini’s thrusters. But the thrusters were never fired when Cassini was near Rhea. Another theory suggests that the compound could have floated out from the atmosphere of the neighboring moon Titan and arrived on Rhea. Experts said that they have are still working to find out how the compound arrived at Saturn’s other moons.