From Europa to other icy moons, scientists are studying how surface features form and what they might reveal about the potential for life.
In a new study published in The Planetary Science Journal, researchers from UCF, NASA 麻豆精品 S檚 Jet Propulsion Lab (JPL) and other institutions explored a unique, spider-like feature in Manann谩n Crater on Europa, one of Jupiter 麻豆精品 S檚 icy moons.
First observed by NASA 麻豆精品 S檚 Galileo spacecraft, the feature may have formed from briny water eruptions beneath the ice, offering clues about subsurface liquid water and potential habitability on Europa.
“Europa is a fascinating moon to study because its subsurface ocean may have the conditions to support life.” 麻豆精品 S� Lauren Mc Keown, assistant professor at UCF
麻豆精品 S淏y understanding surface expressions, we can learn more about processes and conditions where liquid water may exist below the surface, 麻豆精品 S� says Lauren Mc Keown, assistant professor at UCF 麻豆精品 S檚 .
Using Earth 麻豆精品 S檚 lake stars as analogs, combined with field observations, lab experiments and modeling, the researchers hope to gain valuable insights into how these icy features form, which could have implications for future missions that might land on Europa and other icy airless worlds.
Originally from Ireland, Mc Keown 麻豆精品 S檚 interest in space began as a teenager when she first learned about the Cassini spacecraft, which explored Enceladus, a small icy moon of Saturn.
麻豆精品 S淚 was fascinated by the animations showing a water plume shooting miles above the moon 麻豆精品 S檚 surface and the possibility that liquid water, or even an ocean, might exist there, 麻豆精品 S� she says. 麻豆精品 S淚t encouraged me to explore NASA 麻豆精品 S檚 website to learn more about icy planetary surfaces and eventually pursue a career in planetary science at Trinity College Dublin. 麻豆精品 S�
As an icy planetary geomorphologist, Mc Keown studies surface features and processes on icy planets, moons and small bodies.
麻豆精品 S淢y research includes analyzing Martian 麻豆精品 S榮piders, 麻豆精品 S� which are dendritic 麻豆精品 S� branching, tree-like 麻豆精品 S� features that form in the regolith near Mars 麻豆精品 S� south pole, 麻豆精品 S� she says. 麻豆精品 S淣ow, I 麻豆精品 S檓 applying that knowledge to other planetary surfaces, including Europa. 麻豆精品 S�
While Martian spiders form when dust and sand are eroded by escaping gas below a seasonal dry ice layer, Mc Keown believes Europa 麻豆精品 S檚 麻豆精品 S渁sterisk-shaped 麻豆精品 S� feature may have formed after impact, when liquid brine within the icy shell extruded through broken-up ice from impact to form a pattern similar to Earth 麻豆精品 S檚 lake stars.
麻豆精品 S淟ake stars are radial, branching patterns that form when snow falls on frozen lakes, and the weight of the snow creates holes in the ice, allowing water to flow through the snow, melting it and spreading in a way that is energetically favorable, 麻豆精品 S� she says.
Dendritic patterns like these are common in nature, appearing in Lichtenberg figures created by lightning strikes, in beach rilles where tides flow through sand, and in many other systems where fluid flows through porous surfaces.
麻豆精品 S淚 麻豆精品 S檓 fascinated by these beautiful features on Earth, and there is very little research on how lake stars are formed 麻豆精品 S�, Mc Keown says. 麻豆精品 S淭his inspired my team to explore whether similar processes could explain the pattern on Europa, albeit under different pressure and temperature conditions. 麻豆精品 S�
In the study, researchers proposed a new explanation for the feature, informally naming it Damh谩n Alla, Irish for 麻豆精品 S渟pider, 麻豆精品 S� to distinguish it from Martian spider formations. They suggest it may have formed in a way similar to lake stars on frozen Earth lakes, under locally temporary elevated temperatures and pressures caused by an impact that created Europa 麻豆精品 S檚 Manann谩n crater.
麻豆精品 S淟ake stars on Earth are star-shaped or branched melt patterns that form when warmer water rises through thin ice and spreads through overlying slush or snow before freezing, 麻豆精品 S� Mc Keown says. 麻豆精品 S淥n Europa, we believe a subsurface brine reservoir could have erupted and spread through porous surface ice, producing a similar pattern. 麻豆精品 S�
To test this hypothesis, Mc Keown and colleagues conducted field and lab experiments, observing lake stars in Breckenridge, Colorado, and recreating the process in a cryogenic glovebox at JPL, using Europa ice simulants cooled with liquid nitrogen.
麻豆精品 S淲e flowed water through these simulants under different temperatures and found that similar star-like patterns formed even under extremely cold temperatures (-100掳C), supporting the idea that the same mechanism could occur on Europa after impact, 麻豆精品 S� Mc Keown says.
Elodie Lesage, a research scientist at the Planetary Science Institute and co-author of the study, modeled how a brine pool might behave beneath Europa 麻豆精品 S檚 surface after this impact, and the team created an animation illustrating the process.
Observations of Europa 麻豆精品 S檚 icy features have been limited to images from the Galileo spacecraft.
Mc Keown 麻豆精品 S檚 team hopes to resolve this question with higher-resolution imagery from the Europa Clipper mission, a NASA spacecraft scheduled to arrive at the Jupiter system in April 2030.
麻豆精品 S淭he significance of our research is really exciting, 麻豆精品 S� Mc Keown says. 麻豆精品 S淪urface features like these can tell us a lot about what 麻豆精品 S檚 happening beneath the ice. If we see more of them with Europa Clipper, they could point to local brine pools below the surface. 麻豆精品 S�
The findings provide insights for possible patterns on Europa; however, researchers caution against relying solely on Earth analogs to understand other planetary surfaces.
麻豆精品 S淲hile lake stars have provided valuable insight, Earth 麻豆精品 S檚 conditions are very different from Europa 麻豆精品 S檚, 麻豆精品 S� Mc Keown says. 麻豆精品 S淓arth has a nitrogen-rich atmosphere, while Europa 麻豆精品 S檚 environment is extremely low in pressure and temperature. In this study, we combined field observations with lab experiments to better simulate Europa 麻豆精品 S檚 surface conditions. 麻豆精品 S�
Mc Keown is also proud of the collaborative nature of the work.
麻豆精品 S淭his study came together organically and reflects a value that 麻豆精品 S檚 important to me: community, 麻豆精品 S� she says. 麻豆精品 S淚 麻豆精品 S檝e had the opportunity to work with an incredible group of scientists 麻豆精品 S� including JPL Planetary Geologist Jennifer Scully, with whom I collaborated to name the feature 麻豆精品 S� whose multidisciplinary expertise was essential to this research. There are not many Irish planetary scientists, so working together has been rewarding, particularly because many of Europa 麻豆精品 S檚 features have Irish and Celtic names. 麻豆精品 S�
Looking ahead, Mc Keown plans to investigate how low pressure affects the formation of these features and whether they could form beneath an icy crust, similar to how lava flows on Earth to create smooth, ropy textures called pahoehoe.
麻豆精品 S淚 麻豆精品 S檓 setting up a new lab at UCF, called the FROSTIE (Facility for Research Observing Simulated Topography of Icy Environments) Lab, where I 麻豆精品 S檓 designing a chamber specifically for these experiments. I am currently involving students to create icy simulants for this work while continuing to collaborate with JPL, 麻豆精品 S� she says.
Although geomorphology was the main focus of this study, the findings offer important clues about subsurface activity and habitability, which are crucial for future astrobiology research.
麻豆精品 S淚 麻豆精品 S檝e spoken with astrobiologists interested in these patterns, including how microbes might inhabit lakes on Earth, 麻豆精品 S� Mc Keown says. 麻豆精品 S淭here 麻豆精品 S檚 great potential for collaboration across disciplines with this research, and I look forward to connecting with colleagues and students at UCF who are as passionate and excited about this work as I am. 麻豆精品 S�
