February 27, 2024 — Southwest Research Institute is leading two “Precursor Science Investigations for Europa” (PSIE) teams to understand critical topics in advance of NASA’s Europa Clipper mission to the Jupiter moon. Both projects are investigating the connection between Europa’s icy surface and its subsurface, which is thought to contain a potentially habitable ocean. The PSIE program funded five out of 28 proposals submitted, including two from SwRI.
Scheduled to launch in October 2024 and arrive in the Jupiter system in 2030, NASA’s Europa Clipper mission will place a spacecraft in orbit around Jupiter to perform a detailed investigation of Europa, one of the largest of Jupiter’s 90 moons. This precursor work will provide critical context to enable more efficient scientific analysis of Europa Clipper data and drive discoveries and new questions to influence mission planning for the latter half of the prime mission and for any potential extended mission. This will maximize the scientific return from the lifetime of Europa Clipper, which is investigating the “habitability” of Europa. Habitability is a measure of whether Europa could support life and includes the presence of essential ingredients like liquid water, chemical building blocks and an energy source.
“Europa is considered one of the most likely sites in our solar system to potentially find life,” said SwRI Lead Scientist Dr. Kelly Miller, who is leading the “Follow the Energy: Tracing from Europa Surface Chemistry Back to Subsurface Redox Conditions” team. “The most habitable environments at Europa are underneath the surface where there is liquid water. We need to measure and understand the relationship between the properties we measure and observe at the surface, and the properties in those interior environments.”
The availability of chemical energy sources depends on the history of the interior ocean and the abundance of organic and inorganic compounds it contains. The interdisciplinary team will look at the evolution of chemical signatures from Europa’s interior to understand how we can distinguish between different possible interior environments without measuring those environments directly.
“We will combine models, observations, experiments and data science methods with the ultimate goal of improving the interpretation of Europa Clipper datasets,” Miller said. “The last steps of the research will use machine learning to process laboratory data collected from related chemical mixtures by the MAss Spectrometer for Planetary EXploration, or MASPEX, engineering model located at SwRI.”
MASPEX is a groundbreaking new Europa Clipper instrument SwRI developed and built to identify the gas molecules teeming around the Jovian moon. High levels of radiation strip some of these compounds off Europa’s surface. Other compounds might be vented into space from samples that can be traced back to Europa’s presumed subsurface ocean or to bodies of water that could be trapped in the moon’s ice shell. MASPEX will identify those molecules with unparalleled precision.
The second SwRI-led team will specifically track ice shell evolution and material exchange between the surface and subsurface to predict the features likely to provide the best information and context for interpreting Europa Clipper data.
“Ahead of Europa Clipper, what we really need to know is how much the surface can tell us about Europa’s interior and ocean, and that’s the primary motivation of our project,” said Dr. Alyssa Rhoden, a principal scientist in SwRI’s Solar System Science and Exploration Division and leader of the “Tracking 3D Ice Shell Evolution and Material Exchange at Europa” investigation. “Our team will investigate the large-scale processes that affect the ocean and ice shell, and how surface features have developed in response, so that we can better anticipate which parts of Europa’s surface are most likely to contain young material, or even oceanic material. That way, we can probe the parts of Europa we can’t directly observe.”
The team will also incorporate recent laboratory experiments and Earth-based radar observations to reinterpret data collected by NASA’s Galileo mission to Jupiter (in orbit 1995–2003). Improving the understanding of Europa’s ice shell and its spectral properties will allow more rapid and accurate interpretation of Europa Clipper spectrometer data, characterizing Europa’s surface composition in detail, and provide a basis for identifying changes in Europa’s surface since Galileo.
“The breadth of this project lets us go after complex problems in our understanding of Europa — where surface geology, interiors and orbital dynamics are tightly coupled, and we are considering the interactions of different materials and compositions,” Rhoden said. “NASA gave us a huge opportunity by providing support for large teams and encouraging inclusivity, and we can’t wait to get started.”
For more information, visit Planetary Science or contact Deb Schmid, +1 210 522 2254, Communications Department, Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238-5166.