{"id":13799,"date":"2018-05-14T21:34:33","date_gmt":"2018-05-14T13:34:33","guid":{"rendered":"https:\/\/wp-productionenv-bjg9h2g2bgg5b8aa.southeastasia-01.azurewebsites.net\/news\/water-plumes-on-europa-detected-by-galileo-spacecraft\/"},"modified":"2018-05-14T21:34:33","modified_gmt":"2018-05-14T13:34:33","slug":"water-plumes-on-europa-detected-by-galileo-spacecraft","status":"publish","type":"post","link":"https:\/\/starpath.global\/news\/water-plumes-on-europa-detected-by-galileo-spacecraft\/","title":{"rendered":"Water plumes on Europa detected by Galileo spacecraft"},"content":{"rendered":"

STORY WRITTEN FOR CBS NEWS & USED WITH PERMISSION<\/p>\n

\"\"
Artist\u2019s illustration of the Galileo spacecraft, Europa and Jupiter. Credit: NASA\/JPL-Caltech\/University of Michigan<\/figcaption><\/figure>\n

A review of data captured by NASA\u2019s Galileo spacecraft as it orbited Jupiter in the 1990s indicates it likely flew through a plume of water vapor spewing from cracks in the surface of the moon Europa, providing independent evidence water is being released from a vast sub-surface ocean beneath its frozen crust, scientists said Monday.<\/p>\n

The Galileo data are consistent with earlier observations by the Hubble Space Telescope that captured signs of presumed plumes at the limits of detectability. In both cases, the data indicate plumes erupted from roughly the same region, a known thermal \u201chot spot\u201d on the moon\u2019s surface.<\/p>\n

The Galileo data were collected in 1997 during a Europa flyby at an altitude of less than 250 miles. The spacecraft\u2019s magnetometer, used to detect and measure magnetic field strength, and its plasma wave spectrometer, which measured charged particles in the environment, both recorded readings best explained by passage through a plume of water vapor, according to the new analysis.<\/p>\n

The magnetometer detected a field rotation across hundreds of miles and a brief, sharp change in field strength while the plasma wave instrument recorded a substantial increase in the density of charged particles near the spacecraft.<\/p>\n

\u201cThe material that is coming out from Europa is probably electrically neutral, it\u2019s probably dominated by water vapor,\u201d said Margaret Kivelson, professor emerita of Space Physics at the University of California who led the Galileo magnetometer team. \u201cBut there are lots of energetic particles in the environment of Europa and they ionize the material, so they make it an electrically charged.<\/p>\n

\u201cAnd it\u2019s those electrically charged parts of the plume that cause the changes in the magnetic field and change the density of the electrons in the environment that were measured by the plasma wave instrument. So it\u2019s not a direct effect on the environment from the plume, it\u2019s a two-step process.\u201d<\/p>\n

Xianzhe Jia, an associate professor at the University of Michigan who led the team that re-assessed the Galileo data, said the location, duration and variations seen in the magnetometer and plasma wave data are consistent with the presumed plume seen by Hubble.<\/p>\n

\u201cThese results provide strong independent evidence of the presence of plumes at Europa,\u201d he concluded in a paper published Monday in the journal Nature Astronomy.<\/p>\n

Not everyone is convinced. Mike Brown, a planetary scientist at the California Institute of Technology, said in a tweet he is a \u201cbig Europa fan,\u201d but \u201cso far, all of the evidence for plumes on Europa has been hopeful, rather than truly convincing. I\u2019d love there to be plumes, but I think we should all retain a healthier skepticism here.\u201d<\/p>\n

Others found the evidence more compelling. Morgan Cable, an astrochemist at NASA\u2019s Jet Propulsion Laboratory, told Scientific American \u201cup until this paper, I was very skeptical the plume existed. \u2026 But this has made me a believer.\u201d<\/p>\n

Launched in 1989, Galileo became the first spacecraft to orbit Jupiter six years later. Between 1995 and 2003, the nuclear-powered orbiter trained a suite of sophisticated instruments on Jupiter\u2019s turbulent atmosphere and its many moons, focusing on the four large Galilean satellites \u2013 volcanic Io and the icy worlds Europa, Callisto and Ganymede.<\/p>\n

Earlier observations of Europa by NASA\u2019s Voyager probes revealed a chaotic cracked surface that could be explained by tidal stresses, imposed by Jupiter\u2019s gravity, if a layer of warmer ice or even liquid existed below the moon\u2019s frozen crust.<\/p>\n

Galileo made 12 close flybys of Europa and detected disruptions in Jupiter\u2019s magnetic field around the moon that also could be interpreted as evidence of a global sub-surface sea of salty water.<\/p>\n

Since then, Europa and, more recently, Saturn\u2019s icy moon Enceladus, where visible plumes of water vapor were detected and directly sampled by NASA\u2019s Cassini probe, have been considered prime targets in the search for habitable environments \u2014 and possibly life \u2014 across the solar system.<\/p>\n

Life as it is known on Earth requires energy, organic compounds and liquid water, and all three may be present below the surface of Europa. But determining habitability will be a major challenge.<\/p>\n

NASA is designing a spacecraft called the Europa Clipper to study the moon and its environment in a bid to do just that. Expected to launch in the mid 2020s, the Europa Clipper will be equipped with nine instruments, including high-resolution cameras, spectrometers and an ice-penetrating radar to measure the thickness of the crust and to look for signs of sub-surface water.<\/p>\n

The Clipper also will look for evidence of recent water eruptions and search for tell-tale atoms and molecules in the moon\u2019s thin atmosphere that might be left over from past or ongoing geysers. The spacecraft will make repeated flybys of Jupiter and more than 40 close passes by Europa at altitudes as low as 16 miles.<\/p>\n

The European Space Agency also is planning a mission, known as JUICE, for JUpiter ICy moons Exlorer, that will arrive in 2029 and spend three years studying the planet, Europa, Callisto and Ganymede.<\/p>\n

In the meantime, evidence that Galileo flew through a plume of water vapor jetting from the interior of Europa has fired imaginations.<\/p>\n

\u201cThere now seem to be too many lines of evidence to dismiss plumes at Europa,\u201d Robert Pappalardo, Europa Clipper project scientist at JPL, said in a statement. \u201cThis result makes the plumes seem to be much more real and, for me, is a tipping point.\u201d<\/p>\n

If the plumes do, in fact, exist \u201cand we can directly sample what\u2019s coming from the interior of Europa, then we can more easily get at whether Europa has the ingredients for life, Pappalardo added. \u201cThat\u2019s what the mission is after. That\u2019s the big picture.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"

STORY WRITTEN FOR CBS NEWS & USED WITH PERMISSION Artist\u2019s illustration of the Galileo spacecraft, Europa and Jupiter. Credit: NASA\/JPL-Caltech\/University of Michigan A review of data captured by NASA\u2019s Galileo spacecraft as it orbited Jupiter in the 1990s indicates it likely flew through a plume of water vapor spewing from cracks in the surface of the moon […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"inline_featured_image":false,"footnotes":"","_links_to":"","_links_to_target":""},"categories":[2],"tags":[1874,1659,1282,1397,1606,1561,1563,2966],"class_list":["post-13799","post","type-post","status-publish","format-standard","hentry","category-news","tag-astrobiology","tag-europa","tag-europa-clipper","tag-galileo","tag-jupiter","tag-planetary-science","tag-solar-system","tag-university-of-michigan"],"acf":[],"_links":{"self":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/13799"}],"collection":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/comments?post=13799"}],"version-history":[{"count":0,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/posts\/13799\/revisions"}],"wp:attachment":[{"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/media?parent=13799"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/categories?post=13799"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/starpath.global\/blog\/wp-json\/wp\/v2\/tags?post=13799"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}