Trying to understand what a potential life outside the Earth can be, astrobiologists are studying the possibilities of survival of organisms in different environments: from the surface of Mars to the ice-covered oceans of European satellites, the Jovian moon. Today, the Earth remains the only example of a habitable planet; therefore, the study of the survival limits of terrestrial organisms is an important component of astrobiology science.
For this reason, scientists collect data from places on our planet in which life shows incredible wonders of adaptation: from the Arctic to the Antarctic, from warm hydrothermal springs on the ocean floor to acidic rivers. Nevertheless, the Antarctic dry valleys or the deep-sea vents of the Pacific Ocean are not the only places for which astrobiologists study life. Low Earth orbit provides an opportunity to observe Earth life in the harsh conditions of space.
Early in the morning of July 24, 2014, a new astrobiological experiment began its journey from Baikonur cosmodrome in Kazakhstan to the International Space Station. BIOMEX (“biological and Martian experiment”) was launched on board the Russian cargo ship Progress and became one of four experiments to be conducted on the outside of the ISS Zvezda module. Just six hours after launch, the cargo ship successfully docked with the ISS.
BIOMEX contains twelve different experimental packages that are designed to determine the potential of life on Mars. The Institute for Planetary Studies at the German Aerospace Center coordinates the work of BIOMEX, but 25 institutions from all over the world are also involved in the project.
BIOMEX contains various chambers that are filled with biomolecules and organisms, including bacteria, archaea, algae, fungi, lichens, and flies. Different sets of samples dispersed in compartments will be exposed to the external environment. Some samples of biomolecules or organisms are included in the imitation of the Martian soil (from several to multiple layers), while others are presented to the cosmos completely without protection.
Different filters are applied to the sample chambers, which should demonstrate the effects of different levels of radiation. With their help, scientists can simulate the solar radiation that is present on the surface of Mars. Some of the chambers are even filled with a practically Martian atmosphere rich in carbon dioxide.
“To get a real understanding of the behavior of biomolecules in the Martian environment, we need to check various parameters that we might encounter on Mars,” explains Jean-Pierre Paul de Vera from the German Aerospace Center, as well as one of the main participants in BIOMEX. “This means that we will apply - as far as the ISS allows us - the Martian conditions: extreme temperature conditions, the Martian atmosphere with Martian gases in the EXPOSE-R2 chambers, as well as the radiation background - which we can never imitate in Earth laboratories ".
Samples will spend from one to one and a half years outside the space station, and organisms will be monitored using temperature sensors and dosimeters that monitor radiation exposure. The goal is to see how the effects of these diverse pressures and pressures from the environment will affect the survival of organisms and the stability of important cellular components, such as membrane lipids, pigments, proteins and DNA.
The results of the BIOMEX experiment will help astrobiologists to understand whether these biological materials can really cope with the conditions of the space and Martian environment, and whether burial, for example, in Martian soil, affects their survival.
While BIOMEX samples will be located outside the station, scientists on Earth will work with copies of the samples in the laboratory. Here they will imitate the Martian conditions as closely as possible in a controlled laboratory environment and observe land-bound samples using a variety of tools.
At the end of the experiment, BIOMEX samples will be returned to Earth, and scientists will carefully evaluate the results. Already in the laboratory, they will be able to characterize the stability of biomolecules after the postponed conditions of low Earth orbit. Including the traces left by them which can be useful in future missions on detection of traces of life on Mars.
"BIOMEX is exploring the potential of tools for detecting certain biosignatures (pigments, membrane composites, lipids, and so on) in the Martian environment before and after space experiments, as well as during Mars simulation in the laboratory," Dr. de Vera told Astrobiology Magazine.
A set of spectroscopic instruments that astrobiologists use on Earth are similar to those that will be used during flights to Mars in the near future. They include Raman spectroscopes and IR / UV / VIS spectra. Initial lab tests have already shown interesting results. For example, that biosignature changes under the influence of temperature and radiation. Therefore, they are different from those that we are accustomed to observe in terrestrial conditions.
BIOMEX data may also have important applications outside the field of astrobiology. Studying how bio-signatures survive in simulated Martian regolith can be useful for earth archaeologists who are looking for radiation-independent methods (that is, not radiocarbon dating) to study ancient wooden objects. The thermogravimetric methodology used by de Vera and his team, in particular, tests the residual water in the BIOMEX samples after they encounter the space environment. It is also in the area of interest of archaeologists.
“Raman spectroscopy is increasingly used in microbiology, pharmacology and medicine,” says de Vera. “The Robert Koch Institute in Berlin, which collaborates with us, uses this method (in combination with others) to identify microorganisms that may be harmful to health. They need to be identified very quickly to determine if there is a risk for an epidemic. ”
The study of biofilms in space can have some interesting implications for the health of astronauts and people on Earth. On Earth, biofilms are used in some medicinal drinks to trigger the immune system. Studying biofilms in space can help determine whether these drinks are safe for astronauts in orbit or not. There is a possibility that the space environment will lead to mutation of the biofilm and it will become harmful for consumption.
“Drying (removal of water) and radiation protection are crucial issues,” notes de Vera. - The study of irradiated samples will provide more information about how the most resistant microorganisms can effectively protect themselves, and which substances are responsible for their resistance. In the cosmetic and food industries are extremely interested in the results of these studies. "
In fact, the Fraunhofer Institute for Cell Therapy and Immunology in Potsdam, Germany, is already working with two of the organisms that study de Vera and his team. One of them is a highly resistant cyanobacteria, and the other is green algae. Thanks to BIOMEX, these organisms are located in low earth orbit, clinging to the outer side of the International Space Station.
BIOMEX will help astrobiologists understand the habitability of Mars. If life ever arose on Mars and existed on the same biological principles as earth, could those organisms adapt to life on Mars these days?
Investigating this issue, BIOMEX can help shape the future exploration of Mars, develop guidelines for where robots will have to look for signs of life on modern Mars, or signs of ancient life preserved in regolith.
“With data obtained on the basis of selected biomolecules as potential signatures, as well as data on how they behave in space and Mars, we will build a database that will be essential for future research missions to Mars,” says Vera. “This base can serve as a backup or system one, automatically update, and also contain possible or predictable life forms and potential life as it may be hiding.”
“We want to know what the effects of ultraviolet radiation will be on the structure of cells and biofilm in space. This will help us understand what organisms can be made that are resistant to the extreme conditions of space. ”
It is believed that organisms capable of forming a biofilm may be more successful in self-defense from harsh environmental conditions. The ability to produce a biofilm may be important in the early stages of the evolution of life on Earth, when conditions on our planet were different.
The article is based on materials .
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