An organism that can feed on space rocks could shed light on the emergence of life on Earth – and how living creatures may survive on other planets.
The organism, known as Metallosphaera sedula, is a type of bacteria-like microbe that gets its energy from inorganic substances.
In a recent study, an international team led by astrobiologist Tetyana Milojevic from the University of Vienna examined a specific type of ancient bacteria that are known to thrive on extraterrestrial meteorites. By examining a meteorite that contained traces of this bacteria, the team determined that these bacteria prefer to feed on meteors – a find which could provide insight into how life emerged on Earth.
Any extraterrestrial critters in our solar system, given the lack of obvious greenery and movement out there, are likely to be simple microbes. Perhaps they burrow deep under the Martian soil to hide from damaging ultraviolet rays. Or perhaps some lie dormant in asteroids, waiting to land in a friendlier environment. A team of researchers at the University of Vienna has tried to guess how such microbes could survive on their own, and what marks they might leave behind, by studying one of Earth’s hardiest bugs. Now, in a recent Nature publication, they detail exactly what happens when you feed meteorites to microbes.
“I want to squeeze out of this important information related to the search for life,” says Tetyana Milojevic, a coauthor and biophysical chemist at the University of Vienna.
The finding also has implications for the potential of extraterrestrial materials as a source of nutrients and energy for microorganisms on the early Earth billions of years ago. At that time, meteorite bombardment was a lot heavier than it is now. Could primitive microbes have used meteorites as a food source way back then? Did meteorites play a crucial role in the growth and evolution of life on Earth by providing sources of nutrients? It certainly seems plausible.
The study of lithotrophs that thrive on extraterrestrial objects could help astronomers answer key questions about how and where life emerged in our Solar System. It could also reveal whether or not these objects, and the bacteria that they deposited on Earth over time, played an important role in the evolution of life.
For some time, scientists have theorized that life (or the basic ingredients thereof) are distributed throughout the Universe by meteors, comets, and asteroids. Who knows? Perhaps life on Earth (and possibly throughout the cosmos) owes its existence to extreme bacteria that turn inorganic elements into food for organics.