“Europa is my favorite body in the solar system,” Quick confesses. But she notes that different ocean worlds additionally supply promising locations to search for indicators of life. Those embody Enceladus, a small moon of Saturn that, like Europa, has an icy crust with an ocean beneath. Images from the Cassini mission in 2005 revealed that geysers on the south pole of Enceladus spew water and natural molecules into area, feeding Saturn’s outermost ring.
However, Europa is greater than Enceladus and is extra more likely to have a floor coated in icy plates that transfer in a manner much like Earth’s plate tectonics. This kind of exercise would assist mix the substances for all times. Ganymede, one other Jovian moon and the photo voltaic system’s largest, additionally possible has a liquid ocean, however sandwiched between two ice layers; with out an interface between water and minerals, life is much less possible. Other doable locations to look embody Titan, Saturn’s greatest moon, which additionally most likely hides a liquid-water ocean beneath an ice crust. (Quick is an investigator on Dragonfly, a mission to discover Titan, scheduled to launch in 2028.)
To search for the indicators and alerts of habitability, Clipper will use 9 major devices. These will take photos of the floor, search for water plumes, use ground-penetrating radar to measure the icy shell and seek for the ocean under, and take exact measurements of the magnetic area.
The spacecraft will move shut sufficient to the moon to pattern its skinny ambiance, and it’ll use mass spectrometry to determine molecules within the gases it finds there. Another instrument will allow scientists to investigate mud from the floor that has been kicked into the ambiance by meteorite collisions. With any luck, they’ll have the ability to inform if that mud originated from under—from the enclosed ocean or subsurface lakes trapped within the ice—or from above, as fragments that migrated from the violent volcanoes on the close by moon Io. Either situation can be attention-grabbing to planetary geologists, but when the molecules had been natural and got here from under, they might assist construct the case that life may exist there.
ESA’s Juice mission has an analogous suite of devices, and scientists from the 2 groups meet repeatedly to plan for methods to collectively exploit the information when it begins coming in—5 – 6 years from now. “This is really very good for scientists in the planetary community,” says Lorenzo Bruzzone, a telecommunications engineer on the University of Trento who leads the Juice mission’s radar instrument staff. He’s lengthy been concerned in efforts to get to Europa and the remainder of the Jovian system.
Because Juice will go to the opposite ocean-bearing Galilean moons, Bruzzone says, knowledge from that mission could be mixed with Clipper’s to generate a extra complete image of the geological processes and potential habitability of all of the ocean worlds. “We can analyze the differences in subsurface geology to better understand the evolution of the Jupiter system,” he says. Those variations might assist clarify, for instance, why three of the Galilean moons shaped as icy worlds whereas the fourth, Io, grew to become a volcanic hellscape.
Jupiter’s radiation has the potential to intrude with each measurement, turning a significant sign into a multitude of digital snow, like static on a tv display screen.
To be sure these devices work once they get there, engineers and designers for each missions have needed to deal with a raft of challenges. Many of them revolve round power: Europa receives solely a fifth as a lot daylight as Earth. Clipper addresses the issue with gargantuan photo voltaic panels, which is able to span 30 meters when absolutely prolonged. (An earlier proposal for a mission to Europa included nuclear batteries, however that concept was costly, and it was in the end scrapped.)