Methane-producing Processes on Enceladus

Methane-producing Processes on Enceladus

Subject : Science & tech

Context : Recently, NASA’s Cassini spacecraft has detected an unusually high concentration of methane, along with carbon dioxide and dihydrogen, in the moons of Saturn by flying through their plumes.

Concept :

• The giant water plumes erupting from Enceladus have inspired research and speculation about the vast ocean that is believed to be sandwiched between the moon’s rocky core and its icy shell.
• The Cassini spacecraft has 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.

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.
• 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. On Earth, hydrothermal vents on seafloors are known to release methane, but this happens at a very slow rate.

Methanogens on Enceladus

• The team using the newly developed model gave a set of conditions, including dihydrogen concentration and different temperatures to understand if microbes would grow.
• The team writes that 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.
• The results suggest that methane production from hydrothermal vents is not sufficient to explain the high methane concentration detected by Cassini in the plumes.

About Cassini Mission

• It was launched on October 15, 1997 on a seven-year journey to investigate Saturn, its rings, and its moons.
• The spacecraft consists of an orbiter and the European Space Agency’s Huygens Titan probe.
• Cassini arrived at the planet in 2004 and continues to study the Saturn system with 12 different instruments.
• The Huygens probe was deployed from the Cassini spacecraft and landed on the moon Titan in January of 2005.
• The probe entered the clouds of Titan and gathered atmospheric data and images as it parachuted to the surface.
• Cassini-Huygens was a mission of firsts because it was first to orbit Saturn, first landing in the outer solar system and first to sample an extraterrestrial ocean.
• It revealed Titan to be one of the most Earth-like worlds we have encountered and shed light on the history of our home planet.