Enceladus, the sixth largest moon of Saturn, should be the “most promising target” for the European Space Agency (ESA) – this is the conclusion of a report drawn up by a specialist commission led by Zita Martins, a professor at Instituto Superior Técnico. Enceladus is followed by other natural satellites such as Saturn’s Titan and Jupiter’s Europa.
Since January this year, Zita Martins has chaired ESA’s Solar System Exploration Working Group (SSEWG). This time, the astrobiologist also coordinated the work of the expert committee for the “Moons of the Giant Planets” mission, which will be involved in ESA’s missions such as Juice (a probe that will explore Jupiter’s moons), LISA (for the detection and study of gravitational waves in space) and NewAthena (an X-ray telescope).
The purpose of this expert committee was to analyse the scientific advantages of visiting various moons of Jupiter or Saturn, with a focus on studying the habitable conditions in these satellites, looking for signs of life or conditions that would allow it. In a statement published on the ESA website, Zita Martins explains “the mission concepts that we have recommended would provide tremendous scientific return, driving forward our knowledge, and would be fundamental for the successful detection of biosignatures on icy moons”.
The astrobiologist adds that she was very happy to be part of this process, “seeing first-hand the early steps that will potentially lead to the investigation of the moons of the giant planets by ESA. The search for habitable conditions and for signatures of life in the Solar System is challenging from a science and technology point of view, but very exciting”.
The three most common conditions for a “habitable environment” to potentially support life as we know it are the presence of liquid water, a source of energy and a specific set of chemical elements. By fulfilling all these conditions, Enceladus becomes a particularly attractive target – according to the ESA, “the plumes that spew through its icy crust are rich in organic compounds, some of which are key for life. The ocean also seems to hold a powerful source of chemical energy that could fuel living organisms”.
ESA could launch such a mission in the early 2040s with Ariane 6 (which will carry a satellite built at Técnico this summer), arriving at Enceladus around a decade later. According to ESA “the impact of such a mission could be enormous. It would offer Europe – once more – a unique front seat in Solar System science.”
