\u201cThe Juno Microwave Radiometer directly observed Io\u2019s heat output by looking below the surface,\u201d said Scott Bolton, study coauthor and Juno\u2019s principal investigator at Southwest Research Institute in San Antonio. \u201cThe surprising discovery that we could see below a rocky moon\u2019s surface has important implications for studying Earth\u2019s volcanoes. Juno has taught us that if we look with an MWR-type instrument near a volcano on Earth, we might see a similar signature in the subsurface temperature gradient, providing new information on how terrestrial volcanoes work.\u201d<\/p>\n
Fire, ice<\/p>\n
Juno\u2019s Microwave Radiometer was designed by Bolton to peer beneath Jupiter\u2019s cloud tops to investigate the dynamics and composition of the gas giant\u2019s deep atmosphere. The MWR\u2019s six microwave antennas serve as a single instrument, simultaneously detecting microwaves at a wide range of wavelengths, from about half an inch to 20 inches (1.3 to 51 centimeters). During the mission\u2019s extended phase<\/a>, the MWR instrument has provided the opportunity to observe three of the planet\u2019s Galilean moons: Ganymede, Europa, and Io.<\/p>\n \u201cThe technique is novel in that each wavelength explores different depths, providing a new way to characterize the deep atmosphere of giant planets and the subsurface crusts of icy and rocky moons,\u201d said Bolton. \u201cAt Ganymede and Europa, we explored tens of miles below the surface, assuming their ice shells were mostly pure water, but the ability to probe into the volcanic rock at Io was an unexpected discovery.\u201d<\/p>\n During flybys on Dec. 30, 2023, and Feb. 3, 2024, the solar-powered Juno spacecraft came within about 930 miles (1,500 kilometers) of the moon\u2019s surface.<\/p>\n \u201cThe instrument measured Io\u2019s thermal emission at depths ranging from a few inches down to tens of feet. Everywhere we looked, we found the temperature rising by more than 40 degrees Fahrenheit just several feet into the surface \u2014 a gradient far steeper than solar heating alone can explain,\u201d said Shannon Brown, the paper\u2019s lead author at NASA\u2019s Jet Propulsion Laboratory in Southern California.<\/p>\n The data suggests two possible explanations. First, heat could be rising steadily through a conductive crust. While this background heat flow \u2014 measured at 1 to 3 watts per square meter \u2014 is relatively gentle on a local scale (roughly equivalent to a small nightlight glowing under every square yard), across the entire moon it represents a release of energy up to 30 times Earth\u2019s average. Alternatively, the signal could be coming from cooling lava flows, capped by roughly 30 to 35 feet (9 to 11 meters) of solidified crust, that cover about 10% of the moon\u2019s surface at any given time.<\/p>\n","protected":false},"excerpt":{"rendered":"\u201cThe Juno Microwave Radiometer directly observed Io\u2019s heat output by looking below the surface,\u201d said Scott Bolton, study…\n","protected":false},"author":2,"featured_media":818990,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[49,48,66,306],"class_list":["post-818989","post","type-post","status-publish","format-standard","has-post-thumbnail","category-space","tag-ca","tag-canada","tag-science","tag-space"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/818989","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/comments?post=818989"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/818989\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media\/818990"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media?parent=818989"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/categories?post=818989"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/tags?post=818989"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}