Soru

Trace amounts of methane ($CH_4$) have been detected in the atmosphere of Mars. Since solar ultraviolet (UV) radiation rapidly destroys atmospheric methane, its ongoing presence implies a continuous source of replenishment. Two scientists propose different mechanisms for how this methane is generated and released.

Scientist 1
The methane is biogenic, produced by methanogenic microorganisms living in liquid water aquifers deep beneath the Martian surface. These microbes survive in the warm subsurface heated by geothermal activity. During warmer Martian seasons, ground ice thaws, forming fractures through which the accumulated methane escapes into the atmosphere.

Scientist 2
The methane is abiogenic, produced by serpentinization. In this process, liquid water reacts with olivine-rich rocks deep inside the crust to produce hydrogen gas ($H_2$). This hydrogen then reacts with carbon dioxide ($CO_2$) under high temperatures and pressures to form methane. The methane is stored in subsurface ice structures called clathrates, which seasonally destabilize and release the gas.

Which of the following is an underlying assumption shared by both Scientist 1 and Scientist 2?