Shafaqna Science: In late 2013 and early 2014, NASA’s Curiosity rover detected an unexpected surge in methane levels on Mars, spiking to ten times the usual amount before gradually fading over a few months. Since then, Curiosity has observed six more such events, but global measurements of methane have yet to provide any conclusive explanations.
The source of these mysterious methane spikes could be a form of alien life or simply an intriguing chemical reaction. Regardless, something unusual is occurring on the Red Planet.
Methane is a simple molecule made up of one carbon atom bonded to four hydrogen atoms, and both elements are abundantly available in the universe. Mars, in particular, has a plentiful supply of carbon, which forms the backbone of carbon dioxide, the main component of its thin atmosphere.
Hydrogen, a common element on Mars and throughout the universe, is typically found bound to other molecules. To form methane, this hydrogen must be released. On Earth, one way to produce free hydrogen involves the interaction of water with iron- and magnesium-rich rocks, leading to oxidation. This process, known as serpentinization, often involves the mineral olivine, which is abundant on Mars.
Once free, hydrogen can react with carbon dioxide under suitable conditions through a process called Fischer-Tropsch synthesis, resulting in methane. However, this process requires liquid water, which, despite evidence of Mars’ water-rich past—such as dried riverbeds and erosion patterns—is now scarce. The only place liquid water could still exist on Mars is deep underground, within tiny cracks and crevices, much like it is in Earth’s mantle. If liquid water is indeed present below the Martian surface, it could react with minerals to release hydrogen, which might then combine with carbon dioxide to produce methane.