Is it possible that NASA's rover has already found on Mars traces of supposed life that existed on the planet in the past? Scientists at Arizona State University (ASU) are confident about this.
The researchers came to such conclusions when they contrasted the research obtained from the Spirit rover, which he conducted on the territory of the Home Plate – a plateau of layered rocks, the study of which took place in the first half of his third year on Mars, with geological features found within active hot geysers in northern Chile , an area called El Tatio.
Based on the work carried out, the scientists wrote an article with a rather provocative title: 'Silica deposits on Mars show signs of biosignatures in hot springs in El Tatio in Chile'. The article was published in the journal Nature Communications.
Opal silica from the Martian Home Plate (left) and El Tatio's terrestrial finger structures (right).
The ASU team in Chile was led by Stephen Ruff and Jack Farmer from the University of Earth and Space . Detailed analysis showed that the nodal and finger-like structures of silica at El Tatio were incredibly similar to those found on Mars, and include complex sedimentary structures obtained by a combination of biotic and abiotic processes.
“Despite the fact that completely abiotic processes are not excluded for the Martian silica structures, they satisfy the a priori definition of a potential biosignature,” the article says.
Spirit landed on Mars in January 2004, just weeks before its twin, Opportunity, landed on another part of the Red Planet. Both rovers were tasked with looking for signs of past water activity, the initial period of operation of the rovers was calculated for three months. During its mission, it was the Spirit rover in the ancient volcanic hydrothermal environment, in the Gusev crater, that managed to find regolith consisting of opal silica (amorphous SiO2nH2O).
The Spirit rover shows nodal opal silica outcrops in the Home Plate. The white outline allows you to see the typical features of a layered silica rock.
It is believed that the origin of this compound by leaching or precipitation of liquids from hot springs is possible. “However, the potential significance of the characteristic structure of silica has not been recognized,” Ruff and Farmer said in a new study.
The physical environment of El Tatio itself is a rare combination of altitude, low rainfall, high average annual evaporation rates, total daily freeze-thaw conditions, and extremely high incident ultraviolet radiation.
“These conditions represent a better ecological counterpart for Mars than Yellowstone National Park (USA) and other known geothermal sites on Earth,” Ruff explained.
'Our results indicate that the Mars-like conditions of El Tatio are conducive to the formation of unique deposits, including biotic silicate structures that have characteristics incredibly similar to the Home Plate's siliceous rocks. This similarity raises the likelihood that Martian silica structures formed in the same way as on Earth. '
Previously, a team of NASA scientists identified a potential biosignature as 'an object, substance and / or pattern that may be of biological origin, therefore, in order to conclude about the presence or absence of life, more detailed data is required.'
“Since we can neither prove nor disprove a biological origin for finger silica, it is, by this definition, a potential biosignature,” Ruff and Farmer wrote.
The rover Spirit got stuck on Mars in May 2009, stuck in soft ground.
In late January 2010, after months of trying to free the rover, NASA dubbed the wheeled robot a stationary research platform. The lack of mobility and the harsh climate of Mars made it impossible to try to re-establish contact with the robot, it was decided to end them in May 2011.
Researchers are now confident that in the future, a mission equipped with special instrumentation could provide a more accurate assessment of the possible biosignature of silicate structures on the Home Plate. However, this mission should be able to deliver samples to Earth, since a full-fledged microscopic and compositional analysis of rocks, as well as conclusions about the existence of life, can only be made in laboratory conditions.
Space
Sources: Space
