A microbial descendant of some of Earth's earliest life can not only survive by eating meteorites, but also seemingly thrive on the space rocks — a finding that could help us detect signs of past life throughout the universe.
Humans and all other animals need to eat organic matter to survive. The single-celled organism Metallosphaera sedula (M. sedula), however, can produce its energy by eating non-living things, such as metals — which allows it to thrive in some of the most hostile conditions on Earth, including inside volcanoes.
For a new study published on Monday in the journal Scientific Reports, a team led by scientists at the University of Vienna decided to see what would happen if they tried to feed M. sedula some of the meteorite Northwest Africa 1172, which was discovered in 2000.
To that end, they placed cells of the organism on sterilized slabs of the meteorite and fed other cells ground-up bits of it. A third group served as a control, with a diet of chalcopyrite, a copper-iron-sulphur mineral.
Surprisingly, the M. sedula gobbled up the meteorite even more readily than it did the terrestrial food, with its numbers growing far quicker on the former than the latter.
"We found that the reaction is quite happy," researcher Tetyana Milojevic told Motherboard. "Our students in the lab also immediately noticed the cells are very vivid, they're dancing on the space rock."
Using an electron microscope, Milojevic’s team was able to see which specific meteorite metals their bacteria ate and chemically transformed, even after the organisms had died — and the scientists believe this information could help in our hunt for extraterrestrial life.
"We performed this study to reveal microbial fingerprints — metal-containing microfossils — left on rocky extraterrestrial material," Milojevic told Gizmodo. "This should be helpful in tracing biosignatures for the search of life elsewhere in the Universe. If life ever occurred on another planet, similar microbial fingerprints could be still preserved in the geological record."
READ MORE: Scientists Fed an Ancient Earth Organism Space Metals. It Started 'Dancing' [Motherboard]
More on meteorites: NASA Says It Found Building Blocks of Life in Fallen Meteorites