[ad_1]
According to a study published in the journal, the old Mars probably had the best conditions to support life under its surface. Scientific letters of the Earth and planets.
A team of researchers, led by Jesse Tarnas of Brown University, discovered that the chemical energy in the underground regions of the red planet was probably enough for tiny microbes to grow about 4 billion years ago.
"We have shown, based on calculations of physics and basic chemistry, that the old Martian sub-surface probably had enough dissolved hydrogen to feed a global underground biosphere," said Tarnas in a statement. "The conditions in this habitable zone would have been similar to those of the Earth where the underground life exists".
These underground areas of our planet are known as subterranean lithotrophic microbial ecosystems, or SliMEs. Microbes in these ecosystems can not harness energy to feed themselves from the sun; instead, they steal electrons from molecules in their environment, particularly dissolved molecular hydrogen.
In their research, scientists estimate that about 4 billion years ago, there was an underground habitable zone in the Martian crust rich in this hydrogen. According to them, this region could have easily maintained microbial life for hundreds of millions of years.
The team came to its conclusion after having shown that the process by which radiation breaks down water into its constituent hydrogen and oxygen molecules – known as radiolysis – occurred in sufficient quantities to produce a great deal of energy. hydrogen under the Martian surface.
Scientists have long been fascinated by the possibility that Mars once hosted life – an idea that has grown in popularity with the growing evidence that liquid water may have leaked to the surface at some point. However, older models of Martian climate suggest that the temperature rarely reached freezing point, suggesting that the wet periods at the surface may have been brief.
See all best photos of the week in these slideshows
This would probably have detracted from the chances of developing life in the long run, leading some scientists to look for signs of life below the surface.
Although the latest results do not prove that life once existed on Mars, they indicate that if microbes evolved, they would have significant energy resources.
Interestingly, the latest discoveries are maintained even in different climate scenarios. In fact, the amount of hydrogen below the surface available as fuel actually increases in extremely cold climate scenarios. In these situations, a thick layer of ice on the surface would help prevent the hydrogen from escaping from the ground.
"People have the impression that a cold climate in early March is bad for life, but what we are showing is that there is actually more chemical energy for life underground in a cold climate "said Tarnas. "We think this could change people's perception of the relationship between climate and life on Mars."
According to the researchers, the study has important implications for the future exploration of the red planet. For example, areas where the old basement is exposed can be excellent targets in looking for signs of life.
Other groups of scientists have also recently provided evidence that increases the chances that Mars has already hosted life. A study published in the journal Nature, for example, showed that the Mars crust was formed at least 4,547 million years ago, much earlier than expected and at least 100 million years earlier than Earth's.
This means that liquid water could have existed on the surface of the planet at this time and that, therefore, this environment could have been beneficial for life. This is much earlier than the Earth, about 100 million years ago, which means that life may have been born on Mars, although it is still a speculative idea.
[ad_2]
Source link
