The National Aeronautics and Space Administration’s (NASA) Cassini spacecraft reported high levels of methane, carbon dioxide, and dihydrogen on Titan and Enceladus, the moons of Saturn, in 2017. Notably, Titan showcased methane in its atmosphere, while Enceladus boasted a liquid ocean with erupting plumes of gas and water. Recently, an international research team leveraged new statistical methods to ascertain if methanogens, microbes known for methane production, could explain the molecular hydrogen and methane observed.
Key Points: Findings from Cassini
Cassini detected ice particles, salts, hydrogen, and organic molecules in the plumes of the moons, pointing to the possible presence of an ocean similar to those on Earth. Indications of alkaline hydrothermal vents on Enceladus’ seafloor, akin to those supporting methanogens in Earth’s oceans, were also found.
About Methanogens
Most of Earth’s methane is biologically sourced. Microscopic life forms known as methanogens can produce methane as a metabolic byproduct. These organisms do not require oxygen, are found across the globe in locations such as swamps, decaying organic matter, and even the human gut. They can withstand high temperatures and Martian conditions, as per simulation studies. Methanogens are often studied to understand their potential role in global warming.
Possibility of Methanogens on Enceladus
Methane could potentially result from the chemical breakdown of organic matter within Enceladus’ core. The moon’s hydrothermal processes might assist in the creation of carbon dioxide and methane. Furthermore, its hydrothermal vents could even support Earth-like microorganisms such as methanogens.
About Saturn
Saturn, the solar system’s sixth planet from the sun, is renowned for its beautiful ringlets. Although it’s not the only planet with a ring system, none rival Saturn’s in grandeur or complexity. Largely composed of hydrogen and helium, this gas giant has only been visited by a few missions. These include Pioneer 11 and Voyagers 1 and 2 flybys. Cassini orbited Saturn 294 times between 2004 and 2017.
About Titan
Titan, Saturn’s largest moon, is the second-largest moon in our solar system, just slightly smaller than Jupiter’s moon Ganymede. It features liquid rivers, lakes, and seas on its surface filled with hydrocarbons like methane and ethane instead of water. Its atmosphere, primarily nitrogen-based like Earth’s, is four times denser and includes clouds and methane rain.
About Enceladus
Enceladus is a small icy moon notable for the abundance of hydrogen molecules in its water plumes. The gas within these plumes is composed of 98% water, 1% hydrogen, and a mixture of carbon dioxide, methane, and ammonia. Underwater vents on Enceladus resemble those on Earth’s ocean floors, known for their rich sea life.
The evidence of methane, carbon dioxide, and dihydrogen on Saturn’s moons Titan and Enceladus studied through NASA’s Cassini mission stirs up intriguing possibilities about organic life beyond our own planet. This research provides insightful scientific knowledge about these celestial bodies and sets the groundwork for future exploration and answers to some of our biggest cosmological questions.
