The rock of Mars is a rare and precious resource here on Earth. So far, the only samples we have are pieces of meteorites, ejected from the red planet and traveling through the Solar System until they reach Earth.
A small piece of these priceless things has just been made a fascinating use: scientists grounded a small piece of the Martian Beauty Black meteorite and used it to grow extremophile microbes.
This not only demonstrates that life could actually exist in real Martian conditions, but it provides astrobiologists with new biosignatures that they could use to look for signs of ancient life in the crust of Mars.
“Black beauty is among the rarest substances on Earth, it is a unique Martian gap formed by several pieces of the Martian crust (some of them dated at 4.42 ± 0.07 million years) and expelled millions [of] years ago from the Martian surface, ”said astrobiologist Tetyana Milojevic of the University of Vienna in Austria.
“We had to choose a pretty bold approach of crushing a few grams of Martian gemstone to recreate the possible look of Mars’ oldest and simplest way of life.”
If ancient life existed on Mars, it is likely that of all life on Earth it will look like an extremophile. These are organisms that live in conditions that we once thought were too hostile to sustain life, such as subzero, super-salt lakes in Antarctica, or volcanic geothermal springs or the Earth’s lower crust, in the depths. from the seabed.
On the ancient Mars, billions of years ago, we are pretty sure the atmosphere was thick and rich in carbon dioxide. We have a sample of some of the rocks that formed the Martian crust when the planet was just a baby.
Here on Earth, organisms that can fix carbon dioxide and convert inorganic compounds (such as minerals) into energy are known as chemolithotrophs, so the research team considered the type of organism it could have. lived on Mars.
“We can assume that chemolithotrophic-like life forms existed in the early years of the red planet,” Milojevic said.
The microbe they selected was Renewed metallosphaera, a thermoacidophilic archaea found in acidic and hot volcanic sources. It was placed on the Martian ore in a carefully heated bioreactor and gassed with air and carbon dioxide. The team used microscopy to observe the growth of the cells.
In fact, they grew and the fundamental mass of Black Beauty left behind allowed scientists to observe how the microbe used and transformed the material in order to build cells, leaving behind biomineral deposits. They used scanning transmission electron microscopy to study these deposits on an atomic scale.
“Cultivated with Martian scouring material, the microbe formed a robust mineral capsule [sic] of complexed iron, manganese and aluminum phosphates, ”Milojevic said.
“Apart from the massive incrustation of the cell surface, we have observed the intracellular formation of crystalline deposits of a very complex nature (Fe oxides, Mn, mixed Mn silicates). They are unique distinguishing features of the growth of Noah’s Marian Gap, which he did not notice before when this microbe was grown on terrestrial mineral sources and a stony chondritic meteorite. “
This could provide some invaluable data in the search for ancient life on Mars. The Perseverance rover, which arrived on the red planet last week, will specifically search only for these biosigns. Now astrobiologists know what it is Marcus is busy crystalline deposits appear to be easier to identify things potentially similar to Percy samples.
Researchers have also highlighted the importance of using real Martian samples to conduct these studies. Although we have simulated the available Mars regolith and Martian meteorites are rare, we can obtain invaluable information by using the real thing.
Part of Perseverance’s mission is to collect Martian rock samples to return them to Earth, hopefully, over the next decade. Scientists will surely claim the dust, but we have no doubt that some will be earmarked for extremophile research.
“Astrobiology research on Black Beauty and other similar‘ Flowers of the Universe ’may provide invaluable insights for the analysis of returned Mars samples in order to assess their potential biogenicity,” Milojevic said.
The research has been published in Earth and Environment Communications.