Scientists chart the future of solar system exploration
Though rather small, Saturn’s 310-mile-wide (500 km) moon Enceladus also got the star treatment in this latest 10-year report. That’s partly because the Cassini mission saw plumes of liquid erupting from Enceladus in 2005. And where there’s water, the chances of life increase. The plumes also contained unusual amounts of possible biosignatures, such as methane, which may be a byproduct of biology.
Proposal Mission “Orbilandre” would arrive at Enceladus in the 2050s, orbit the moon for 18 months, and then the entire craft would descend to the moon’s surface. By then it will have passed through some of these intriguing plumes, which are so active that their rejected material is creating a thin ring around Saturn.
Once on the surface, the Orbilander would spend two years looking for signs of biology. Enceladus’ surface is relatively safe for spacecraft, as it lacks the intense radiation baths of, for example, Jupiter’s moon Europa. According Nasa“Enceladus has most of the chemical ingredients necessary for life, and likely has hydrothermal vents that spew hot, mineral-rich water into its ocean.”
Astrobiologists are particularly excited about the proposed Enceladus mission. Associate professor of ecology and evolutionary biology at the University of Arizona, Regis Ferriere – who is a mathematician with an ecological bent – tells Astronomy that “Enceladus may be one of our best chances of finding [still existing] life in our solar system.
Ferriere was part of a team that published a article 2021 in natural astronomy suggesting that the data produced by Cassini shows that “the observed plume composition is a likely outcome in model simulations that include microbial activity, whereas it is an unlikely outcome in simulations that do not include only abiotic activity”. [non-biological] process.
In other words, the chemicals found in the Enceladus plumes would make After meaning if microbes were involved. And that’s where the new mission comes in.
“We won’t know just with the data from Cassini,” says Ferriere. “The Orbilander is a fantastic opportunity to collect new data that could solve the mystery. The Orbilander is designed to characterize the organic molecules in the plume, and therefore has the potential to detect the building blocks of Earth-like cells, such as amino acids or lipids.
But even if the orbilandre discovers that Enceladus’ plume chemistry is not produced by life, Ferriere says the data would be important: “We would still learn a lot about Enceladus’ habitability and, more generally, extraterrestrial environments that harbor liquids water.”