In news NASA’s Cassini spacecraft had detected an unusually high concentration of methane, along with carbon dioxide and dihydrogen, in the moons (Titan and Enceladus) of Saturn by flying through their plumes (in 2017).
It found that Titan has methane in its atmosphere and Enceladus has a liquid ocean with erupting plumes of gas and water.
An international research team has used new statistical methods to understand if methanogenesis or methane production by microbes could explain the molecular hydrogen and methane.
What are the Findings of Cassini?
Cassini found ice particles, salts, hydrogen and organic molecules in the plumes, tentative hints of an ocean that is similar to Earth’s oceans in composition.
There is also evidence for alkaline hydrothermal vents on Enceladus’ seafloor, similar to those that support methanogens in Earth’s oceans.
What are Methanogens?
Most of the methane on Earth has a biological origin.
Microorganisms called methanogens are capable of generating methane as a metabolic byproduct.
They do not require oxygen to live and are widely distributed in nature.
They are found in swamps, dead organic matter, and even in the human gut.
They are known to survive in high temperatures and simulation studies have shown that they can live in Martian conditions.
Methanogens have been widely studied to understand if they can be a contributor to global warming.
Possibility of Methanogens on Enceladus:
Methane could be formed by the chemical breakdown of organic matter present in Enceladus’ core.
Hydrothermal processes could help the formation of carbon dioxide and methane.
Enceladus’ hydrothermal vents could be habitable to Earth-like microorganisms (Methanogens).
Few missions have visited Saturn: Pioneer 11 and Voyagers 1 and 2 flew by; But Cassini orbited Saturn 294 times from 2004 to 2017.
