In a continuing quest for discovering the possibility of life on Mars, researchers report that a lake bed could have harboured life. The researchers are closely examining a long-vanished lake at a site called Yellowknife Bay. This lake, it is inferred, may have been around from hundreds to tens of thousands of years and could have provided the ecosystem to sustain life. The Curiosity team infers that the lake may have had Earth like habitable environment.
The researchers are using the findings from the Curiosity rover, a space vehicle which was launched by NASA last year, to determine if the lake bed did hold life. On an oxygen-free planet, the team reckons that the microbes would have had to derive energy from a process called chemolithotrophy. In this process, the microbes process inorganic reduced compounds as an energy source. The researchers used experiments conducted by Curiosity’s SAM (Sample Analysis at Mars) instrument package. Equal sized samples from the lake bed and from the planet’s surface were heated by SAM. It was found that the samples from the lake bed gave out more carbon dioxide and produced the gas at lower temperatures when compared to the surface samples. This led to the conclusion that the lake bed sample may have contained organic matter for this to happen.
Conclusions are far from being drawn though. Challenges in proving life on Mars are also present on the Martian surface. Glavin of the curiosity team admits, “we can’t say anything about the origin of this [organic] carbon.” One of the sources of the organic matter could be the meteorites that fall on Mars every year. The environment surrounding the Gale crater, in which the Yellowknife Bay is located, also does not seem to have had the conditions to support life.
Sources: Science Mag