New instruments will study potential habitability of Jupiter’s moon Europa

Two Southwest Research Institute instruments were launched aboard NASA’s Europa Clipper spacecraft on Oct. 14 from the agency’s Kennedy Space Center. The spacecraft is designed to conduct a detailed reconnaissance of Jupiter’s moon Europa, investigating whether it could hold conditions suitable for life.

The SwRI-developed MAss Spectrometer for Planetary EXploration (MASPEX) and Ultraviolet Spectrograph (Europa-UVS) are among nine science instruments and a gravity science investigation that were developed to explore Europa, Jupiter’s fourth-largest moon and one of the most likely locations for potential life in our solar system. In the 1990s, NASA’s Galileo mission yielded strong evidence that Europa, which is about the size of Earth’s moon, has a liquid ocean beneath an icy crust of unknown thickness. This global ocean could have at least twice as much water as Earth.

“The ability to characterize this ocean remotely is key—MASPEX has a mass resolution 50 times finer than anything that has flown to space before,” said SwRI Senior Vice President Dr. Jim Burch, who serves as MASPEX’s principal investigator. Burch leads the Institute’s Space Sector, with three divisions devoted to space science, solar system science and space systems. “MASPEX can differentiate between molecules with almost identical masses based on the energy binding the atoms. It also differentiates isotopes—atoms with equal numbers of protons but a different number of neutrons. These capabilities are crucial to revealing the habitability of Europa.”

Europa-UVS is the sixth in a series of SwRI-built ultraviolet spectrographs, benefitting greatly from the design experience gained by its team from the Juno-UVS instrument, which is currently operating in Jupiter’s harsh radiation environment on NASA’s Juno spacecraft.

“UVS is designed to hunt down and study potential plumes emanating from surface cracks on Europa,” said Dr. Kurt Retherford, principal investigator for the UVS instrument and a senior program manager at SwRI. UVS will look at the composition and chemistry of Europa’s atmosphere to understand its source, structure and variability. It will search for and characterize plumes in terms of activity and the nature of subsurface water reservoirs.

“Once UVS detects any potential plumes, the spacecraft might fly through them, allowing MASPEX to ‘sniff’ the volatile gases,” said Burch.

The mass spectrometer is designed to measure the molecular and isotopic composition of these gases, offering insight into the oxidation state of the moon’s subsurface ocean and potential metabolic energy sources for potential microbial life.

“With these precise measurements, the composition of the gases will reveal the story of the interior and whether the conditions for life exist beneath the icy surface of Europa,” Burch explained.

Another UVS is en route to Jupiter now aboard ESA’s Jupiter Icy Moons Explorer (Juice) to orbit both Jupiter and its moon Ganymede.

“Having two UVS instruments in the Jupiter system making measurements will offer exciting complementary science possibilities,” said Retherford. “Juice is primarily studying Ganymede, but it will fly past Europa twice.”

Europa Clipper is NASA’s largest solar-powered spacecraft for a planetary mission, and it will enter a long, looping orbit around the gas giant Jupiter to perform repeated close flybys of the moon over a four-year period. In total, the mission will perform nearly 50 flybys at altitudes ranging from 16 miles to 1,700 miles (25 kilometers to 2,700 kilometers).

The MASPEX instrument team includes scientists from SwRI, SETI, Washington University, Arizona State University, Imperial College London and the University of Franche-Comté. The Europa-UVS instrument team includes scientists from SwRI, The University of Texas at San Antonio, SETI, the Planetary Science Institute, the Royal Institute of Technology in Sweden and the University of Cologne in Germany.