The ability of a planet to support life depends on several characteristics. The presence of liquid water or oxygen. The position of the planet in relation to its host star, for example. Researchers now point out that the presence of iron could also be a kind of condition sine qua non.
theis an essential component of life. This has been known for a long time. But some (United Kingdom) have just updated the mechanisms by which the presence of could have influenced the development of complex life forms. A discovery that could be used to characterize the probability of finding life on other planets.
“The initial quantity of iron in terrestrial rocks is defined by the conditions of planetary accretion during which the metallic core of the Earth separated from itsrocky, explains Jon Wade, a planetologist at the University of Oxford, in a . Too little iron in the rocky part of the planet, such as on Mercury, and life appears unlikely. Too much iron, as on Mars, and water may be difficult to maintain on the surface for periods relevant to the evolution of a ».
The helping hand of fate
On Earth, on the other hand, the conditions would have been ideal to retain water on the surface. Its solubility inwould also have made it readily available to marine life. At least until the – the increase in the level of oxygen in the terrestrial – about 2.5 billion years ago. At that point, life had to find ways to make more efficient use of an iron that had become scarce. Because it was nonetheless vital. His solution: complexification.
“This implies that the conditions to support the emergence of simple life forms are not sufficient to ensure further evolution to complex life forms as well. Further selection by severe environmental changes may be necessary. Such changes on a planetary scale may be rare or random, which means that themay also be weak ”, remarks Hal Drakesmith, a biologist at the University of Oxford. But knowing how crucial the role of iron is could guide researchers in their quest for life elsewhere in the universe.