While space rocks are great for gathering all kinds of data about our solar system, they are also rather difficult to get your hands on. Sure, tons of space matter enters our atmosphere every day, but most of it burns up before it hits the ground, and if it doesn’t burn up, there’s a high probability that any surviving meteorites landed in the water. Or someplace equally difficult to get to. This is why scientists rely heavily on Earth analogs for research.

If we can understand how biology or geology works here on Earth, we can apply that to other worlds, at least in terms of possibilities and maybe probabilities.

Researchers recently analyzed rocks from the Persian Gulf near Oman in an effort to understand just where microorganisms called methanogens could exist. Their results were published in the journal JGR Biosciences with lead author Alta Howells, who examined rocks called ophiolites. These are rocks that once were part of an ancient seafloor and, at some point, reacted with water to produce hydrogen gas. The process is called serpentinization, and that gas can be used by microorganisms for energy.

The team wanted to find out what effect this process and these rocks could have on the biodiversity of any ecosystem hosted within. Why? Well, as Howells explains: It is believed that processes like serpentinization may exist throughout the universe, and evidence has been found that it may occur on Jupiter’s moon Europa and Saturn’s moon Enceladus.

Those icy worlds are key targets in the search for life beyond Earth.

Unfortunately, they discovered that not all of the ophiolite ecosystems could support methanogens, but that’s okay. Those rocks could host sulfate-consuming organisms instead. And the research also suggested that methanogens require more energy in these types of rocks as opposed to freshwater or marine sediments, possibly due to high pH levels.

It’s always good to add ideas to our toolbox when it comes to searching for life beyond Earth. Howells notes: If we can develop simple models with energy supply as a parameter to predict the occurrence and activity of life on Earth, we can deploy these models in the study of other ocean worlds.

More Information

ASU press release

“Energetically Informed Niche Models of Hydrogenotrophs Detected in Sediments of Serpentinized Fluids of the Samail Ophiolite of Oman,” Alta E. G. Howells et al., 2022 February 27, JGR Biogeosciences