Since long we have been hearing lots of news related to life on mars and planets other than earth . Various research and studies claimed that there might be some clue of sustainable life but confirmation has been the issue over this.
In recent years, Mars has looked more and more like a place where past life might have flourished. Now, some researchers believe the Red Planet may have the ingredients for life to exist in the present. You just have to go underground.
In research published today in Nature Geoscience, a JPL-led team looked at the amount of oxygen in Martian soil, and their findings were influenced by two key recent discoveries. First, the Curiosity rover had found rocks on Mars that were heavily oxidized, possibly the result of water permeating into the rocks. Second is the recent research that revealed sources of briny water on Mars. Looking deeply into the abundance of oxygen in the rocks and the potential oxygen in subsurface reservoirs of briny water, the scientists found there was enough oxygen to sustain simple kinds of subsurface life.
“We found something very surprising: Many brines can exist in different places on Mars,” says Vlada Stamenkovic, a JPL scientist and lead author on the paper. “They fully suffice to allow the aerobic breathing for microbes and even sponges, which are the simplest animals.”
Now this is something that reveals up the possibility of life throughout various pockets on the Red Planet—though, make no mistake, this study doesn’t prove there is life. And if life is there, it may be hard to test for. NASA tends to avoid any area on Mars that may have water deposits for fear of contaminating any life there with hardy Earth bacteria. This means that most rovers, including the upcoming Mars 2020 rover, are left looking for evidence of past life.
But there is evidence of these kind of underground brine lakes, including at the South Pole of Mars. These would be the best spots to look for such life. That’s especially true because the breakdown of oxygen would give any microbes—or even smaller macrobes—something to breath. “Oxygen matters for mars more than we ever dreamt of, and it allows a new way of looking at life on Mars,” Stamenkovic says.
It also changes the view of Mars we’ve held since the 1960s, where the Mariner missions discovered a seemingly dry, desolate world. We’ve since looked for evidence of past water on Mars, which we have in abundance. That meant past life, and maybe an outside chance of extremely hardy present day microbes, a minority view.
LIFE ON MARS
The possibility of life on Mars is a subject of significant interest to astrobiology due to its proximity and similarities to Earth. To date, no proof has been found of past or present life on Mars. Cumulative evidence shows that during the ancient Noachian time period, the surface environment of Mars had liquid water and may have been habitable for microorganisms. The existence of habitable conditions does not necessarily indicate the presence of life.
Scientific searches for evidence of life began in the 19th century, and they continue today via telescopic investigations and deployed probes. While early work focused on phenomenology and bordered on fantasy, the modern scientific inquiry has emphasized the search for water, chemical biosignatures in the soil and rocks at the planet’s surface, and biomarker gases in the atmosphere.
Mars is of particular interest for the study of the origins of life because of its similarity to the early Earth. This is especially so since Mars has a cold climate and lacks plate tectonics or continental drift, so it has remained almost unchanged since the end of the Hesperian period. At least two-thirds of Mars’s surface is more than 3.5 billion years old, and Mars may thus hold the best record of the prebiotic conditions leading to abiogenesis, even if life does not or has never existed there.
Following the confirmation of the past existence of surface liquid water, the Curiosity and Opportunity rovers started searching for evidence of past life, including a past biosphere based on autotrophic, chemotrophic, or chemolithoautotrophic microorganisms, as well as ancient water, including fluvio-lacustrine environments (plains related to ancient rivers or lakes) that may have been habitable. The search for evidence of habitability, taphonomy (related to fossils), and organic compounds on Mars is now a primary NASA and ESA objective.
The findings of organic compounds inside sedimentary rocks and of boron on Mars are of interest as they are precursors for prebiotic chemistry. Such findings, along with previous discoveries that liquid water was clearly present on ancient Mars, further supports the possible early habitability of Gale Crater on Mars. Currently, the surface of Mars is bathed with radiation, and when reacting with the perchlorates on the surface, it may be more toxic to microorganisms than thought earlier. Therefore, the consensus is that if life exists —or existed— on Mars, it could be found or is best preserved in the subsurface, away from present-day harsh surface processes.
The atmosphere of the planet Mars is composed mostly of carbon dioxide. The atmospheric pressure on the Martian surface averages 600 pascals (0.087 psi; 6.0 mbar), about 0.6% of Earth’s mean sea level pressure of 101.3 kilopascals (14.69 psi; 1.013 bar). It ranges from a low of 30 pascals (0.0044 psi; 0.30 mbar) on Olympus Mons’s peak to over 1,155 pascals (0.1675 psi; 11.55 mbar) in the depths of Hellas Planitia. This pressure is well below the Armstrong limit for the unprotected human body. Mars’s atmospheric mass of 25 teratonnes compares to Earth’s 5148 teratonnes; Mars has a scale height of 11.1 kilometres (6.9 mi) versus Earth’s 8.5 kilometres (5.3 mi).
But these findings mean that there may be a few places where life forms need not be so extreme—and that even after the surface of a planet becomes inhospitable, there may be more than meets the eye going on just below the surface.
“The last 40 years, people didn’t think oxygen would matter at all for life on Mars,” Stamenkovic says. “We wanted to change that dogma.”
SOURCE – Futurism