Phosphate - an essential chemical ingredient for life - may have been more abundant in the habitable environments on early Mars than those of early Earth, according to a study published online in Nature Geoscience.
The phosphate that was incorporated into the earliest organisms on Earth must have come from minerals, but phosphate-containing minerals on the Earth’s surface dissolve very slowly. The resulting limited availability of phosphate in aqueous environments is thought to have been a hurdle to the emergence of life on Earth.
In a laboratory setting, Christopher Adcock and colleagues measured the dissolution of the phosphate-containing minerals that are thought to be most common on Mars. They found that these minerals are much more soluble, and thus release more phosphate into water, than those most common on Earth. Their measurements suggest that phosphate concentrations in wet environments on early Mars may have been twice those of early Earth.
In an accompanying News and Views article, Matthew Pasek writes that, “although it is unclear whether life ever arose on Mars, much less if it required phosphate… with readily available phosphate, life [on Mars] would have faced one less obstacle.”