Some lucky astronomers work with the rarest material in the world. True Martian meteorites are extremely rare, but invaluable for understanding Martian geology. Now one of the most famous meteorites, nicknamed Black Beauty, is helping shed light on a much more speculative area of science: Martian biology.
Black Beauty, officially known as North West Africa 7034, is one of the most visually impressive of all Martian meteorites. It consists of a type of volcanic breccia, a series of rock fragments that have joined together to form a fine-grained pattern. Researchers have used it to study everything from water content on Mars to geological history.
NWA 7034, known as Black Beauty, was the Martian meteorite that was used for the bioalteration experiment as part of the latest research at the University of Vienna.
Photo credit: NASA
Most of this research was done non-destructively. In this final round, however, a team of researchers from the University of Vienna had to test part of the meteorite destructively by chopping off a piece and crushing it into extremely fine grains. They then did something that had never been done before: brought earth-bound bacteria to a purely Martian substrate.
The bacteria they introduced, known as Metallosphaera sedula, are a type of bacteria known as thermoacidophilic chemolithotrophe. Simply put, it prefers high temperature, high acidity environments very similar to the environment in which Black Beauty is believed to have originated on Mars about 4.4 billion years ago. It also likes to eat stones.
Image of M. sedula, the bacteria used in the experiment.
Photo credit: Microbe Wiki / Kenyon University
When the scientists introduced M. sedula into a substrate made up of the grains of the meteorite, they took note of how the bacteria ingested the constituents of the meteorite and, using biological activity, turned them into useful compounds on which to grow themselves. Most fascinatingly, the researchers introduced M. sedulla into other mineralogical substrates with only slightly more mundane origins – a range of minerals from the earth itself, as well as a more normal chondritic meteorite.
In a word, the results in the results of bacterial growth on the three different substrates were “distinguishable”. This means that M. sedula made a significant biochemical change to the fragments of Black Beauty that the other two test substrates did not. Given the environmental conditions on Mars associated with the formation of Black Beauty, it is not entirely out of the question that a bacterium similar to M. sedula could have been present on the red planet and are performing the same type of biotransformation on Mars could rock that existed on the surface of Mars at that time.
UT video about our possible life on Mars.
Interestingly, scientists could still see the remaining biosignatures of such a biotransformation on Mars today. With the landing of the Perseverance rover and another rover coming from China in the near future, more modern equipment will clean the surface of Mars like never before. One of the tell-tale signs that devices are being searched is biosignatures. The research of the team at the University of Vienna will help to support this search, even if a small part of one of the most spectacular meteorites in the world had to be sacrificed.
University of Vienna – Living a pure Mars design
UT – Is there life on Mars?
Nature Communications – Chemolithography at the Noachian Martian Breccia NWA 7034 using experimental microbial biotransformation
Image of M. sedula interacting with the fragments of Black Beauty. Photo credit: Tetyana Milojevic