Gathering intel
Finding hard evidence of life is difficult — particularly on Europa, where it would likely lie under layers of ice.
“Biologists still struggle to put a definition on what is alive and what is not alive,” says Curt Niebur, a scientist at NASA Headquarters in Washington, D.C. “It’s hard enough [searching for life] on Earth, so doing that halfway across the solar system with a robotic spacecraft is even more difficult, more complicated, and more challenging.”
Because of the seemingly uninhabitable surface conditions, any probe sent to the moon would theoretically have to drill down some unknown distance before sampling for life. Scientists are working on ways to achieve this, but in the near future, they’ll only be able to take measurements remotely.
Niebur is working on just that as the program scientist for NASA’s Europa Clipper mission, which aims to launch in 2023. By studying the moon in detail, the mission will determine whether Europa has conditions suitable for life.
Entering orbit around Europa, the craft will use nine instruments to investigate the moon’s surface and interior. At closest approach, Europa Clipper will speed by just 3 miles (5 km) above the surface, low enough to fly through geyser bursts. A mass spectrometer and dust mass analyzer will study particles ejected in the bursts, while an ultraviolet spectrograph will image the plumes from afar and identify their composition. Other instruments will look for thermal signatures on the surface to detect new bursts, while ice-penetrating radar will measure the thickness of the icy shell. A magnetometer will measure the strength of the moon’s magnetic field to probe its interior. These data will help scientists determine how deep the ocean might be, as well as its salinity.