Space explorers not only consider Mars as a possible shelter for another life – liquid oceans trapped under ice ices are found on some other moons of the solar system. Chris Mackay, for example, is in love with Mars. This red, dusty, rust-ridden world is no longer as attractive as it used to be, but still.
“I’ve been obsessed with life on Mars for many years,” the NASA planetologist admits, who spent most of his career looking for signs of life on the Red Planet, in an interview with the BBC. “This is the temptation of the highest level. I give up my first love and go to another one, which showed me what I wanted to see. ”
The new object of Mackay’s attachment is Enceladus, Saturn’s moon, covered in ice. Examined by the NASA space probe and the European space agency Cassini, this satellite spouts jets of water from the south pole – most likely from the liquid ocean a few kilometers below the surface. “Cassini” found that this water contains all the vital ingredients: carbon, nitrogen and hydrogen.
“I think that’s what you need,” says McKay. “From the standpoint of astrobiology, this is an extremely entertaining story.”
But the “Cassini” is only a few weeks before he meets his death in the atmosphere of Saturn. “We have to fly through this trail in search of life,” he says. “We have developed a new mission specifically for this purpose, to fly low and slowly through the train, collect samples and find evidence of life.”
The proposed mission currently competes with NASA with five other missions of the future – to comets, asteroids and planets. “Now we have the opportunity to fight,” says McKay. “But the story is damn good: we’re going to find life, and you?” I think we will win in this competition, because the goal is extremely attractive. ”
Enceladus, however, is only one of several ice-covered worlds of the solar system with liquid water and, possibly, microscopic life. Other candidates include three moons of Jupiter: Europe, Callisto and Ganymede. Even the distant moon of Neptune Triton can be habitable.
Europe, perhaps, is the most famous goal for study. Back in the 1960s, astronomers speculated that life on this moon could be. Arthur Clarke imagined on her plants growing under the ice. Observations of the Galileo probe in the late 1990s showed that Europe has an ocean of water 15-20 kilometers deep beneath a cracked ice crust on the surface. There may also be areas in which water lakes are trapped in ice traps just a few kilometers away.
And although we can wait tens of years before we get to Enceladus, Europe will soon be scrutinized. ESA is building a spacecraft known as JUICE – Jupiter Icy Moon Explorer. In 2022 the probe will be launched to Jupiter in order to study Europe, Ganymede and Callisto in detail.
NASA also plans to send in the mid-2020s the mission of Europa Clipper. This robotic probe will have to fly around Europe about 40 times. Meanwhile, in the Jet Propulsion Laboratory in Pasadena, engineers are already developing the next stage: design landing modules and sampling systems on these ice worlds.
In frozen conditions it is extremely difficult to work. In addition to remote control, a serious problem will be one attempt to break through a few kilometers of ice to the liquid. NASA is considering options for launching landing missions, which will eventually drill ice to collect samples. While this problem is not solved, but the JPL works a lot of smart people.
McKay’s team is working on various concepts, including the european approach and the anchor system, which will use the heated teeth to hold the instruments on ice. Sampling technologies from under the surface include a robot on a thermonuclear element that can “leak” through the bark. Another project is a drill that will cut into the ice and return the samples through a pipe for analysis.
At the moment, scientists have some prototypes in the laboratory, but before the start of the mission, another 15-20 years, so there will be other suggestions. Working decision yet, but the time to search for them – completely. Find any life, even the tiniest, on the once considered dead satellites will definitely become one of the most high-profile discoveries of all time. This will mean that there are a lot of life in the universe.
“Extraordinary hypotheses require extraordinary evidence,” says McKay. “In my opinion, there is no more extraordinary hypothesis than the existence of life in another world – the second genesis.”