image: Shown here are yellow sulfurous emissions from the Borup Fjord Pass. view more
Credit: D. Gleeson.
In a fjord in Canada scientists have found a landscape similar to one of Jupiter's icy moons: Europa. It consists of a frozen and sulphurous environment, where sulphur associated with Arctic bacteria offer clues for the upcoming missions in the search for traces of life on Europa.
It is not easy to find a place on Earth where ice and sulphur come together, supposedly like on Europa, Jupiter's moon. Nonetheless, this place has been located at Borup Fjord Pass in the Canadian High Arctic. Here the sulphurous yellow emissions contrast with the whiteness of the environment, creating images similar to those captured at Jupiter's satellite.
US researchers have now verified that the sulphur involved in the life cycle of Arctic microorganisms has some characteristics that could help to detect biological remains on Europa. Large space agencies like NASA and the European Space Agency are already in the process of preparing missions.
"We have discovered that elemental sulphur (S) can contain morphological, mineralogical and organic 'biosignatures' linked to bacterial activity. If they are found on Europa, this would suggest the possible presence of microorganisms," as explained to SINC by Damhnait Gleeson, lead author of the study and currently member of the Centro de Astrobiologia (INTA-CSIC, Spain).
The 'biosignatures' are associated with needle and rhomboid sulphur shapes in which mineralised remains of microorganisms and extracellular material appears. Thanks to electron microscopy and X-ray diffraction techniques, the formation of a rare type of sulphur has also been observed in association with organic components: the rosickyite. What is more is that small quantities (parts per million) of protein, fatty acids and other biomolecules have appeared in the sulphurous material.
"There is much evidence of bacterial activity," highlights Gleeson, who wonder if in the Europa's icy crust, or the ocean or lakes supposedly beneath it, there could be a similar microbial community that uses sulphur as their source of energy.
The researcher conducted the study, which has now been published in the Astrobiology journal, as a member of NASA's Jet Propulsion Laboratory and the University of Colorado in the USA. She is currently working as a scientist in the Centro de Astrobiologia in Río Tinto (Spain), a place similar to Mars.
References:
Damhnait F. Gleeson, R.T. Pappalardo, M.S. Anderson, S.E. Grasby, R.E. Mielke, K.E. Wright, A.S. Templeton. "Biosignature Detection at an Arctic Analog to Europa". Astrobiology 12 (2): 135-150, 2012. Doi:10.1089/ast.2010.0579.
Journal
Astrobiology