Radiation May Hinder Search For Life On Mars and Europa

Radiation from the sun and galactic cosmic rays may have a hindering effect on the search for signs of alien life in the solar system, according to a recent report. Studies have suggested that galactic radiation can lead to the fast degradation of biological material on the surface of Mars as well in the ocean of Jupiter's Moon Europa. The two celestial bodies are currently the main targets for conducting a search for extraterrestrial life, both past and present.

As per a report, the thick atmosphere of Earth protects life on the planet from the destructive effects of galactic cosmic rays (GCRs), which come in larger doses than sun or Jupiter radiations. However, the Red Planet's thin atmosphere and Europa's nearly absent atmosphere is no match for protecting them from the harmful effects of GCRs, subsequently leading to an exposure to high levels of radiation that can be wipe out the fossils that existed in these two worlds.

Numerous scientists hope to find evidence in the form of biological molecules like amino acid or fossilized microorganisms that would point to the existence of life on Mars in the past. However, finding such proof would mean that such molecules should still persist on Europa or Mars. A NASA planetary scientist, Alexander Pavlov, conducted a study to find out if amino acids could withstand radiation similar to that experienced on Martian surface. Pavlov and his team mixed amino acids with rocky material akin to that found on the Red Planet, and simulated conditions that a rover would likely come across.

On the basis of the observations, it was found that radiation degraded amino acids in a span of 50 million years. Furthermore, the researchers simulated historically wet areas on Mars by adding water to the surface sample, and it was concluded that water sped up the degradation process and wiped out few of the bio-markers in as less as 500,000 years, and all within 10 million years. "More than 80 percent of the amino acids are destroyed for dosages of 1 megagray, which is equivalent to 20 million years," Alexander Pavlov said. "If we're going for ancient bio-markers, that's a very big problem." In addition, though cold temperatures can slow down the degradation process it would not be enough for long term preservation according to the scientists.

The discovery could mean bad news for missions to Mars that plan to look for signs of ancient life on the planet's surface. A similar study was also conducted by another NASA planetary scientist, Luis Teodoro, to find out the effect of radiation on Europa, one of Jupiter's four Galilean moons. After stimulating the conditions of Europa, the results were seen to be similar to those found by Pavlov and team for Mars. In addition, Europa is also exposed to another radiation source, which is emitted from Jupiter. Based on the researches, the scientists have reportedly expressed that perhaps one has to look deep under the surface to find signs of life.