It has been found that some microscopic organisms survive in the harsh climate of Mars for hundreds of millions of years, according to new research, in a discovery that may have implications for the search for life forms on the “red planet”.
A team of researchers from across the United States and Slovenia, including Professor of Chemistry at Northwest University Brian Hoffman, created an environment that mimics the Martian environment with cold temperatures, dry weather and high levels of radiation exposure, and in the result they found that certain strains of terrestrial bacteria survived. for longer than expected. This discovery indicates that any ancient Martian microbes, if they existed in earlier times, lived under the soil of Mars, and that humans should be very careful and careful not to contaminate this planet with terrestrial microbes.
On Tuesday, the journal Astrobiology published a scientific paper detailing the scientists’ findings.
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In a statement, Dr. Hoffman said that he and his colleagues “have found that terrestrial pollution on Mars will remain there permanently – over timescales of thousands of years. As a result, scientific efforts to search for life on Mars will become more complex. If microbes evolve on Mars, they can survive to this day, so bringing samples from Mars could contaminate Earth.”
Mars as we know it today is extremely dry and very cold, with average temperatures on the surface of about minus 80 degrees Fahrenheit, and even colder at the poles of the planet. Because it lacks a magnetic field, unlike Earth, Mars is also bombarded with radiation from both the Sun and the larger universe.
According to Dr. Hoffman, “Since the Martian atmosphere does not have flowing water or a large amount of water, the cells and spores will dry up there. It is also known that the temperature of the surface of Mars is almost like dry ice, so it must be very frozen.”
So, in a lab, he and his colleagues created conditions similar to the environment on Earth, and exposed six types of terrestrial bacteria and fungi to gamma rays. [أشعة كهرومغناطيسية أشد طاقة من أشعة إكس وتتأتى نتاج تفاعلات نووية تحدث غالباً في الفضاء وفي التفاعلات النووية والمفاعلات النووية] and proton radiation.
One bacterial strain, Deinococcus radiodurans (“terrible radiation-resistant organism”), deserves its nickname “Conan the Bacterium” because of its tough nature. The researchers found that these bacteria, when buried under the equivalent of Martian soil, were able to absorb a dose of radiation equal to 28,000 times the lethal dose for humans. Researchers estimate that it can live for 1.5 million years at a depth of only 10 centimeters below the surface of the Red Planet, and that it will live up to 280 million years when it is buried a full 10 meters below the surface.
If similar bacteria evolved on Mars, scientists don’t expect them to have survived in the 2 to 2.5 billion years since water flowed freely on Mars, according to Michael Daly, a professor of pathology at the Regulated Services University for the Health Sciences in Bethesda, Maryland. But the periodic effects of meteorites may have led to the melting of enough water from time to time to provide spots of water for these microorganisms over time.
They hypothesize that “periodic melting may allow for intermittent resettlement and dispersal. This raises the possibility that if life forms on Mars evolved, future missions would observe them,” said Dr. Daly.
It remains that missions such as the “Mars Sampler”, which will return samples of Martian soil taken by the US space agency’s Perseverance rover, will find their way to Earth in the early 2030s.