Scientists will scan the data transmitted by the Huygens spacecraft from Titan for chemical signs of life in an attempt to identify the source of the Saturnian moon's methane
Scientists will scan the data transmitted by the Huygens spacecraft from Titan for chemical signs of life in an attempt to identify the source of the Saturnian moon's methane. Methane is constantly decaying at the hands of ultraviolet radiation and therefore there must be a source inside Titan that replenishes the stock in the atmosphere.
Life is one of the possibilities, although some believe that it is not particularly likely, as a source of hydrocarbons in addition to geological processes. The surface is too cold for biology, but bacteria can survive in the oceans inside Titan, say scientists who spoke to the BBC website.
Methane can also be released from its trapped, networked form created by a geological process known as serpentinisation. None of these methods require biology.
Titan's atmosphere consists mainly of nitrogen (95%) as well as methane and other organic molecules. Because of this, Titan is considered a deep-frozen version of Earth as it was 4.6 billion years ago.
Rain of liquid methane falls on Titan, from which the methane flows in rivers, and is probably collected in underground basins. However, the ultraviolet radiation would destroy all the methane on Titan within 10 million years if it was not renewed all the time.
"We cannot completely dismiss the chances that there is life on Titan," said Dr. Francis Raulin, one of the three interdisciplinary scientists who worked on the Huygens project. "There is no chance of life on the surface, because there is no liquid water. "However, the models of the subsurface hypothesize the existence of an ocean at a depth of 100 kilometers whose upper surface is 300 kilometers below the surface of the ground (and it must be remembered that the ground itself is ice-water, AB) "If the models are correct, the ocean may be composed mainly of liquid water And about 15% ammonia at a temperature of 80 degrees Celsius (above zero)." says Dr. Rollin. "We have water, organic matter, we have everything on Titan that is necessary for life," he explained.
"If methane-producing bacteria have colonized this life zone, scientists may discover their chemical signature by measuring the ratio of two isotopes of carbon: C12 and C13. Living cells prefer C12, so the compounds produced by the living things should be free of heavy isotopes like C13. Thus they predict a high ratio of C12 to C13.
The scientists will be able to measure this ratio in data launched from the Huygens Mass Chromatograph Mass Spectrometer (GCMS). "The GCMS can detect the C12/C13 ratio. We haven't done it yet, we're still working on it," says Sushil Atreya, a professor of planetary sciences at the University of Michigan, and a member of the GCMS team.
"This is one of the factors that we will have to take into account to find out how much methane is re-created, however, Prof. Atria prefers the geological processes and serpentinization in particular as the cause of renewing the methane stock on Saturn's moon.
In serpentinisation, geothermal activity creates methane by oxidizing metals such as iron, chromium and magnesium that may be found in the crustal rocks beneath Titan's surface. Another possibility is that the methane molecule is trapped in the so-called water ice matrix (in the form of methane hydrate). Dr. Rollin also believes that these geological processes are an essential source of methane
