Researchers are making significant strides in understanding the potential for life on Europa, one of Jupiter’s icy moons. A recent study published in The Planetary Science Journal examines a unique spider-like feature located within the Manannán Crater. This feature has drawn the attention of scientists from various institutions, including the Planetary Science Institute and NASA’s Jet Propulsion Laboratory (JPL).
Co-author Elodie Lesage, a research scientist at the Planetary Science Institute, explained that the spider-like structure could have formed through the eruption of melted brines following an impact event. “This would mean that it can inform us on subsurface properties and brine composition at the time of the impact,” Lesage said.
The lead author, Lauren McKeown from the University of Central Florida, and her team are also studying similar features found on Mars, which they refer to as “Martian spiders.” These branching, tree-like structures are created by the erosion of dust and sand due to gas escaping from beneath a dry ice layer. By applying this knowledge to Europa, the researchers propose that the “asterisk-shaped” feature may have developed in a similar manner after an impact.
The team informally named the Europa feature Damhán Alla, which means “spider” in Irish. This naming helps to distinguish it from the formations observed on Mars. The researchers conducted both field and laboratory experiments to test their hypothesis. They observed lake stars in Breckenridge, Colorado, and recreated the formation process in a cryogenic glovebox at JPL, using ice simulants cooled with liquid nitrogen.
McKeown highlighted their findings, stating, “We flowed water through these simulants under different temperatures and found that similar star-like patterns formed even under extremely cold temperatures (-100°C), supporting the idea that the same mechanism could occur on Europa after impact.”
The research draws parallels between the newly discovered features on Europa and natural formations on Earth. For instance, lake stars on Earth exhibit radial, branching patterns that emerge when snow accumulates on frozen lakes. The weight of the snow creates holes in the ice, allowing water to flow through and melt the snow in a manner that is energetically favorable.
While observations of Europa’s icy surface have primarily relied on data from the Galileo spacecraft, which operated until 2003, the team is optimistic that the upcoming Europa Clipper mission, scheduled to arrive in the Jupiter system in April 2030, will provide higher-resolution imagery to further investigate these features.
Although the study focused on geomorphology, the implications extend to understanding subsurface activity and habitability on Europa. “Using numerical modelling of the brine reservoir, we obtained constraints on the reservoir potential depth (up to 3.7 miles below the surface) and lifetime (up to a few thousands of years post-impact),” Lesage noted. This information is critical for future missions exploring potential habitable environments beneath icy surfaces.
Looking ahead, McKeown plans to examine how low pressure affects the formation of these features and whether similar structures could develop beneath an icy crust, akin to how lava flows on Earth create smooth textures.
The research not only enhances our understanding of Europa but also sheds light on the conditions that may support life beyond Earth. As the scientific community continues to explore these icy worlds, the findings from this study will serve as a foundation for future astrobiology research.
