UA Scientists Have Their Eyes on Europa

The largest spacecraft to ever explore the solar system blasted into the sky above NASA's Kennedy Space Center in Cape Canaveral, Florida, on Oct. 14. NASA's Europa Clipper will orbit Jupiter and make 49 planned flybys of its moon Europa to study the moon's icy shell and help researchers better understand what lies beneath.

Scientists at the University of Arizona Lunar and Planetary Lab, which has longstanding expertise imaging other worlds in unprecedented detail, will participate in many aspects of the mission, with emphasis on developing the data processing methods to produce beautiful images, mosaics and topographic data.

Europa Clipper carries nine scientific instruments to provide a comprehensive study of the moon Europa, which is covered by a thick, icy crust, under which scientists believe lies a vast ocean of liquid water. This makes Europa one of the prime destinations in the solar system to search for extraterrestrial life, as scientific evidence suggests that the ingredients for life may exist on Europa right now. If the mission determines Europa is habitable, it may mean there are more habitable worlds in our solar system and beyond than previously imagined.

At the heart of the science instrument suite on board the orbiter is the Europa Imaging System, or EIS (pronounced "ice"), which will capture Europa's valleys, ridges, dark bands and other features in detail. Developed at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, EIS consists of a wide-angle camera and a narrow-angle camera, each with an 8-megapixel sensor, that will map Europa with high-resolution color and stereoscopic images. 

"I look forward to seeing the surface of Europa at a level of detail we have never seen before," said Sarah Sutton, a research and development engineer and scientist in the U of A Lunar and Planetary Laboratory who will work on Europa image processing and planning. 

Sutton, who has researched Mars for most of her career, is part of a group at the university led by Regents Professor Alfred McEwen, who is also principal investigator of NASA's HiRISE camera on the agency's Mars Reconnaissance Orbiter, which has been photographing the surface of Mars for over a decade and a half. 

"It will be exciting to test our ideas about Europa's surface evolution and to discover new things about this intriguing ocean world," Sutton said. "I hope we get to observe active changes happening on the surface, or even actively erupting plumes of gas and dust."

McEwen, who serves as deputy principal investigator on the EIS instrument, wants to answer key questions, including: How deep is Europa's ocean, and how thick is the ice shell? Is Europa currently active? Are there eruptions or plumes that can carry subsurface materials to the surface? Are there complex organic molecules on Europa's surface?

"EIS will be essential or helpful to all of these objectives," he said. "At closest approach, about 50 kilometers (30 miles) from the moon's surface, we'll be able to image small patches of the surface down to about 50 centimeters (20 inches). Together, our cameras will provide essential information needed for a future landing mission to Europa."  

Another instrument, REASON, short for Radar for Europa Assessment and Sounding: Ocean to Near-surface, is an ice-penetrating radar designed to look inside Europa's icy crust and study the nature of the interior. Reaching as deep as 30 kilometers (nearly 20 miles) into Europa's icy crust, the observations will allow scientists to build a picture of how the crust of Europa evolved to its present state and how it functions today, according to Lynn Carter, associate professor of planetary sciences and University Distinguished Scholar who serves a co-investigator on the REASON team. 

"Our observations will place real constraints on the nature of the icy crust and how it changes through time and interacts with the subsurface ocean," she said. "This is a really critical part of the puzzle for determining if Europa could be habitable. I'm excited that we could see something new and unexpected."

Europa Clipper is the first mission designed to conduct a detailed study of Jupiter's moon Europa. During its journey, the spacecraft will travel 1.8 billion miles (2.9 billion kilometers) to reach Jupiter in April 2030. To power its extensive instrument suite in the faint sunlight that reaches Jupiter, Europa Clipper carries the largest solar arrays NASA has ever used for an interplanetary mission. With arrays extended, the spacecraft spans 100 feet from end to end. With propellant loaded, its launch weight registered at a whopping 13,000 pounds. 

Elizabeth Turtle of APL, who serves as the principal investigator on the EIS camera, obtained her doctorate at the U of A's Lunar and Planetary Laboratory and later held a faculty position there. All in all, at least 20 other LPL alumni work on the Europa Clipper mission in one form or another. 

Managed by Caltech in Pasadena, California, the Jet Propulsion Laboratory led the development of the Europa Clipper mission in partnership with the Johns Hopkins Applied Physics Laboratory for NASA's Science Mission Directorate in Washington. The Applied Physics Laboratory designed the main spacecraft body in collaboration with the Jet Propulsion Laboratory and NASA's Goddard Space Flight Center, Marshall Space Flight Center and Langley Research Center. The Planetary Missions Program Office at the Marshall Space Flight Center in Huntsville, Alabama, executes program management of the Europa Clipper mission.