Opinion
Mission Europa: What secrets will this moon of Jupiter reveal?
Summary
- Nasa’s mission to a Galilean moon of Jupiter that’s encrusted in a thick shell of ice will let us know if its bulky ocean has signs of life. The lure, of course, is water—a vital resource that we’ve failed so starkly to secure on Earth.
Nasa’s Europa Clipper mission took off on 14 October to study Europa, one of Jupiter’s four moons discovered by Galilei Galileo in 1610. The Italian’s discovery came at great personal cost, but also spun off modern astronomy.
What we are about to find out in a few years will tell us whether there are any practical uses of Galileo’s 17th century discovery. It’s a tip of the hat, if you will, to not only the spirit of scientific enquiry, but also to, well, spirit itself—the need for gutsy dissent and debate.
In Dialogue Concerning the Two Chief World Systems, the astronomer, when accused of heresy, says, “The truth is the truth. Is the Mother Church so fearful of science? Our Earth behaves as do all the wandering stars. I have observed that there are four moons that circle Jupiter in orbits of their own.
So does our Moon the Earth as the Earth describes her orbit around the sun." To which, his Vatican interrogator replies, without a shred of evidence: “No. You are deranged." This, for challenging the time’s orthodoxy that all heavenly motion was around the Earth.
Also read: Historic NASA mission to Jupiter moon blasts off
Evidence gathering is the aim of the US space agency’s Europa mission, which will work in tandem with Europe’s Jupiter Icy Moons Explorer (or Juice), launched last year to study all four moons. Europa is encrusted in thick ice, as we have known since Voyager 1 and 2 sent us close-ups in 1979 revealing a gleaming white sphere.
Scientists now expect to find a 100km-thick layer of water and/or ice covering its rocky interior. It is reckoned to hold three times the quantity of all water on Earth. Does this oceanic moon also have vital elements that support life here—carbon, hydrogen, nitrogen, oxygen, phosphorous and sulphur? Probes will look for signs.
Could it, perchance, also be swarming with organisms of the kind found—and studied—living under Lake Vostok’s sheets of ice in Antarctica? What else do we know? Europa has very few impact craters. Its surface is probably still forming.
It has mysterious dark fractures which may be cracks in its ice shell that open and close perhaps twice during its orbit of 3.6 Earth days. The Europa Clipper will travel 2.9 billion kilometres and is expected to enter Jupiter’s orbit in April 2030.
Its findings from dozens of flybys will be awaited with bated breath. As Europa Clipper programme scientist Curt Niebur told CNN, “It’s a chance for us to explore not a world that might have been habitable billions of years ago, but a world that might be habitable today."
Also read: Nasa to explore Jupiter’s ocean world — What is Europa Clipper Mission?
This mission has all the hallmarks of humans trying to flee a chaotic globe for a new one. We have messed up our blue planet, a name rendered ironic by the havoc we have wreaked on our water resources with man-made climate change.
Today, only 0.5% of Earth’s water is usable and available freshwater, and a rapidly warming world is reducing that supply, according to the UN. Over the past 20 years, terrestrial water storage—including soil moisture, snow and ice—has dropped at a rate of 1cm per year. The Arctic cap is shrinking fast.
Our water security is at threat, with the poor set to bear the brunt of its scarcity. In a 1961 novel, Polish sci-fi writer Stanislaw Lem gave us the portrait of an oceanic planet called Solaris.
His ocean, though, was sentient, capable of playing tricks on our minds. If it were on Europa, it might welcome us to peer into drops of Jupiter’s moon—and urge us to take better care of the great blue globe we inhabit.
