Researchers have made significant strides in understanding the surface features of Europa, one of Jupiter’s icy moons, which could provide insights into the potential for extraterrestrial life. A new study published in The Planetary Science Journal details a unique spider-like formation discovered in the Manannán Crater, revealing clues about the subsurface conditions and the possibility of brine reservoirs.
The study, conducted by a team from the Planetary Science Institute, the University of Central Florida, and NASA’s Jet Propulsion Laboratory, proposes that this spider-like feature formed from the eruption of melted brines following the impact that created the crater. As coauthor Elodie Lesage, a research scientist at the Planetary Science Institute, explained, “This spider-like feature might have formed through the eruption of melted brines following the Manannán impact. This would mean that it can inform us on subsurface properties and brine composition at the time of the impact.”
The lead author, Lauren McKeown from the University of Central Florida, has also explored similar formations on Mars, known as Martian ‘spiders.’ These branching features arise from the interaction of escaping gas with dust and sand. The team’s findings on Europa suggest that the asterisk-shaped formation may have been created in a markedly different manner, post-impact.
To illustrate the formation process on Europa, McKeown referenced lake stars—radial patterns seen on frozen lakes on Earth. “Lake stars form when snow falls on frozen lakes, allowing water to flow through the snow and create holes in the ice,” she noted. “On Europa, we believe a subsurface brine reservoir could have erupted after an impact, spreading through porous surface ice to create a similar pattern.”
The researchers named the feature “Damhán Alla,” which means “spider” in Irish, to differentiate it from Martian formations. To validate their hypothesis, they conducted field and laboratory experiments, including observations of lake stars in Breckenridge, Colorado and simulations using Europa ice analogs cooled with liquid nitrogen at NASA’s Jet Propulsion Laboratory.
“We flowed water through these simulants at various temperatures and found that star-like patterns formed even at extremely cold temperatures (-100°C), supporting our theory that similar mechanisms could occur on Europa post-impact,” McKeown explained.
While the team has relied on imagery captured by the Galileo spacecraft in 1998, they are optimistic that the upcoming Europa Clipper mission, scheduled to arrive at the Jupiter system in April 2030, will provide higher-resolution images. This mission could significantly enhance our understanding of Europa’s surface features.
McKeown emphasized the challenges of studying Europa, stating, “While lake stars have provided valuable insight, Earth’s conditions are very different from Europa’s.” The moon has a low-pressure environment and extremely cold temperatures, making direct comparisons difficult. Through a combination of field observations and lab experiments, the team aimed to better simulate the conditions present on Europa.
In future research, McKeown plans to examine how low pressure could influence the formation of these features and whether they might develop beneath an icy crust, akin to how lava flows on Earth create smooth textures known as pahoehoe.
The implications of this study extend beyond geomorphology, offering vital information regarding subsurface activity and the habitability of Europa. “Using numerical modeling of the brine reservoir, we estimated a potential depth of up to 3.7 miles below the surface and a lifetime of several thousand years post-impact,” Lesage noted. This data is essential for upcoming missions aiming to explore habitable environments within Europa’s icy shell.
The Planetary Science Institute, a nonprofit organization founded in 1972, plays a crucial role in solar system exploration. With research spanning various celestial bodies, the institute contributes to numerous NASA and international missions, emphasizing the importance of understanding planetary processes and the potential for life beyond Earth.
