{"id":8380,"date":"2022-04-20T22:30:08","date_gmt":"2022-04-21T02:30:08","guid":{"rendered":"https:\/\/spaceandplanetarynewswire.com\/?p=8380"},"modified":"2022-04-20T22:31:10","modified_gmt":"2022-04-21T02:31:10","slug":"explanation-for-formation-of-abundant-features-on-europa-bodes-well-for-search-for-extraterrestrial-life","status":"publish","type":"post","link":"https:\/\/spaceandplanetarynewswire.com\/?p=8380","title":{"rendered":"Explanation for Formation of Abundant Features on Europa Bodes Well for Search for Extraterrestrial Life"},"content":{"rendered":"
This artist\u2019s conception shows how double ridges on the surface of Jupiter\u2019s moon Europa may form over shallow, refreezing water pockets within the ice shell. This mechanism is based on the study of an analogous double ridge feature found on Earth\u2019s Greenland Ice Sheet. (Image credit: Justice Blaine Wainwright)<\/figcaption><\/figure>\n

Europa is a prime candidate for life in our solar system, and its deep saltwater ocean has captivated scientists for decades. But it\u2019s enclosed by an icy shell that could be miles to tens of miles thick, making sampling it a daunting prospect. Now, increasing evidence reveals the ice shell may be less of a barrier and more of a dynamic system \u2013 and site of potential habitability in its own right.<\/p>\n

Ice-penetrating radar observations that captured the formation of a \u201cdouble ridge\u201d feature in Greenland suggest the ice shell of Europa may have an abundance of water pockets beneath similar features that are common on the surface. The findings<\/a>, which appear in Nature Communications<\/em> April 19, may be compelling for detecting potentially habitable environments within the exterior of the Jovian moon.<\/p>\n

\u201cBecause it\u2019s closer to the surface, where you get interesting chemicals from space, other moons and the volcanoes of Io, there\u2019s a possibility that life has a shot if there are pockets of water in the shell,\u201d said study senior author Dustin Schroeder<\/a>, an associate professor of geophysics at Stanford University\u2019s School of Earth, Energy & Environmental Sciences<\/a> (Stanford Earth). \u201cIf the mechanism we see in Greenland is how these things happen on Europa, it suggests there\u2019s water everywhere.\u201d<\/p>\n

A terrestrial analog<\/strong><\/p>\n

On Earth, researchers analyze polar regions using airborne geophysical instruments to understand how the growth and retreat of ice sheets might impact sea-level rise. Much of that study area occurs on land, where the flow of ice sheets is subject to complex hydrology \u2013 such as dynamic subglacial lakes, surface melt ponds and seasonal drainage conduits \u2013 that contributes to uncertainty in sea-level predictions.<\/p>\n

Because a land-based subsurface is so different from Europa\u2019s subsurface ocean of liquid water, the study co-authors were surprised when, during a lab group presentation about Europa, they noticed that formations that streak the icy moon looked extremely similar to a minor feature on the surface of the Greenland ice sheet \u2013 an ice sheet that the group has studied in detail.<\/p>\n

\u201cWe were working on something totally different related to climate change and its impact on the surface of Greenland when we saw these tiny double ridges \u2013 and we were able to see the ridges go from \u2018not formed\u2019 to \u2018formed,\u2019\u2009\u201d Schroeder said.<\/p>\n

Upon further examination, they found that the \u201cM\u201d-shaped crest in Greenland known as a double ridge could be a miniature version of the most prominent feature on Europa.<\/p>\n

Prominent and prevalent<\/strong><\/p>\n

Double ridges on Europa appear as dramatic gashes across the moon\u2019s icy surface, with crests reaching nearly 1000 feet, separated by valleys about a half-mile wide. Scientists have known about the features since the moon\u2019s surface was photographed by the Galileo spacecraft in the 1990s but have not been able to conceive a definitive explanation of how they were formed.<\/p>\n

Through analyses of surface elevation data and ice-penetrating radar collected from 2015 to 2017 by NASA\u2019s Operation IceBridge, the researchers revealed how the double ridge on northwest Greenland was produced when the ice fractured around a pocket of pressurized liquid water that was refreezing inside of the ice sheet, causing two peaks to rise into the distinct shape.<\/p>\n

\u201cIn Greenland, this double ridge formed in a place where water from surface lakes and streams frequently drains into the near-surface and refreezes,\u201d said lead study author Riley Culberg, a PhD student in electrical engineering at Stanford. \u201cOne way that similar shallow water pockets could form on Europa might be through water from the subsurface ocean being forced up into the ice shell through fractures \u2013 and that would suggest there could be a reasonable amount of exchange happening inside of the ice shell.\u201d<\/p>\n

Snowballing complexity<\/strong><\/p>\n

Rather than behaving like a block of inert ice, the shell of Europa seems to undergo a variety of geological and hydrological processes \u2013 an idea supported by this study and others, including evidence of water plumes<\/a> that erupt to the surface. A dynamic ice shell supports habitability since it facilitates the exchange between the subsurface ocean and nutrients from neighboring celestial bodies accumulated on the surface.<\/p>\n

\u201cPeople have been studying these double ridges for over 20 years now, but this is the first time we were actually able to watch something similar on Earth and see nature work out its magic,\u201d said study co-author Gregor Steinbr\u00fcgge, a planetary scientist at NASA\u2019s Jet Propulsion Laboratory (JPL) who started working on the project as a postdoctoral researcher at Stanford. \u201cWe are making a much bigger step into the direction of understanding what processes actually dominate the physics and the dynamics of Europa\u2019s ice shell.\u201d<\/p>\n

The co-authors said their explanation for how the double ridges form is so complex, they couldn\u2019t have conceived it without the analog on Earth.<\/p>\n

\u201cThe mechanism we put forward in this paper would have been almost too audacious and complicated to propose without seeing it happen in Greenland,\u201d Schroeder said.<\/p>\n

The findings equip researchers with a radar signature for quickly detecting this process of double ridge formation using ice-penetrating radar, which is among the instruments currently planned for exploring Europa from space.<\/p>\n

\u201cWe are another hypothesis on top of many \u2013 we just have the advantage that our hypothesis has some observations from the formation of a similar feature on Earth to back it up,\u201d Culberg said. \u201cIt\u2019s opening up all these new possibilities for a very exciting discovery.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"

Europa is a prime candidate for life in our solar system, and its deep saltwater ocean has captivated scientists for decades. But it\u2019s enclosed by an icy shell that could be miles to tens of miles thick, making sampling it a daunting prospect. Now, increasing evidence reveals the ice shell may be less of a…<\/p>\n","protected":false},"author":71,"featured_media":8382,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0,"fifu_image_url":"https:\/\/earimediaprodweb.azurewebsites.net\/Api\/v1\/Multimedia\/4efc961c-5515-41db-9ca6-c286a8069373\/Rendition\/low-res\/Content\/Public","fifu_image_alt":"Explanation for Formation of Abundant Features on Europa Bodes Well for Search for Extraterrestrial Life","footnotes":""},"categories":[207],"tags":[],"class_list":["post-8380","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-research"],"_links":{"self":[{"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/posts\/8380","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/users\/71"}],"replies":[{"embeddable":true,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=8380"}],"version-history":[{"count":2,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/posts\/8380\/revisions"}],"predecessor-version":[{"id":8383,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/posts\/8380\/revisions\/8383"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=\/wp\/v2\/media\/8382"}],"wp:attachment":[{"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=8380"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=8380"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/spaceandplanetarynewswire.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=8380"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}