"Long before it's in the papers"
June 04, 2013

RETURN TO THE WORLD SCIENCE HOME PAGE


Organic chemicals detected at Saturn moon

March 26, 2008
Courtesy NASA
and World Science staff

NASA’s Cas­si­ni space­craft de­tected a sur­pris­ing or­gan­ic “brew” erupt­ing like a gey­ser from Sat­urn’s moon En­cel­a­dus dur­ing a close fly­by on March 12, re­search­ers say.

Sci­en­tists think the moon may al­so have liq­uid wa­ter, which along with the or­gan­ic chem­i­cals and oth­er fea­tures al­ready found could pro­vide most of the pre­req­ui­sites for life.

Geyser-like jets emerge from En­cela­dus in this Cas­sini snap­shot. (Cour­tesy NA­SA)


Cas­si­ni mis­sion in­ves­ti­ga­tors say they’re amazed that this ti­ny moon is so ac­tive and brim­ming with wa­ter va­por and or­gan­ics, which are the chem­i­cal in­gre­dients of life as it exists on Earth.

New heat maps of the sur­face indi­cated un­ex­pect­edly high tem­per­a­tures in the south po­lar zone, with warm tracks run­ning the length of gi­ant fis­sures. Ad­di­tion­al­ly, sci­en­tists say the or­gan­ics “taste and smell” like some of those in com­ets.

A big sur­prise “is that the chem­is­try of En­cel­a­dus, what’s com­ing out from in­side, re­sem­bles that of a com­et,” said Cas­si­ni team mem­ber Hunt­er Waite of the South­west Re­search In­sti­tute in San An­to­nio, Tex­as. “To have pri­mor­di­al ma­te­ri­al com­ing out from in­side a Sat­urn moon raises many ques­tions on the forma­t­ion of the Sat­urn sys­tem.” 

“En­cel­a­dus is by no means a com­et,” he added. Its ac­ti­vity “is pow­ered by in­ter­nal heat while com­et ac­ti­vity is pow­ered by sun­light. En­cel­a­dus’ brew is like car­bon­at­ed wa­ter with an es­sence of nat­u­ral gas.”

The Cas­si­ni in­stru­ment for which Waite is prin­ci­pal in­ves­ti­ga­tor, the Ion and Neu­tral Mass Spec­trom­e­ter, saw a much high­er-than-ex­pect­ed dens­ity of vol­a­tile gas­es, wa­ter va­por, car­bon di­ox­ide and car­bon mon­ox­ide, as well as or­gan­ic ma­te­ri­als, he said.

The heat maps also show that the so-called ti­ger stripes, gi­ant fis­sures that are the source of the gey­sers, are rela­t­ively warm along most of their lengths, re­search­ers said. The mea­sure­ments found tem­per­a­tures of at least mi­nus 135 de­grees Fahr­en­heit. The warmest re­gions along the ti­ger stripes cor­re­spond to two of the jet loca­t­ions seen in Cas­si­ni im­ages.

“These spec­tac­u­lar new da­ta will really help us un­der­stand what pow­ers the gey­sers. The sur­pris­ingly high tem­per­a­tures make it more likely that there’s liq­uid wa­ter not far be­low the sur­face,” said John Spen­cer, Cas­si­ni sci­ent­ist at the South­west Re­search In­sti­tute in Boul­der, Colo. The jets blast off the sur­face in­to space.

“En­cel­a­dus has got warmth, wa­ter and or­gan­ic chem­i­cals, some of the es­sen­tial build­ing blocks needed for life,” said Den­nis Mat­son, Cas­si­ni proj­ect sci­ent­ist at NASA’s Je­t Pro­pul­sion Lab­o­r­a­to­ry in Pas­a­de­na, Ca­lif. “We have quite a rec­i­pe for life on our hands, but we have yet to find the fi­nal in­gre­di­ent, liq­uid wa­ter.” Sci­en­tists are hop­ing that mi­cro­bi­al life might turn out to ex­ist in a wet in­te­ri­or of the moon, though oth­er fac­tors, such as a lack of sun­light, could make that dif­fi­cult.

Cas­si­ni came with­in 30 miles (48 km) of En­cel­a­dus, re­search­ers said; when it flew through the plumes it was 120 miles (190 km) away. An ad­di­tion­al fly­by is sched­uled for Au­gust.


* * *

Send us a comment on this story, or send it to a friend

 

Sign up for
e-newsletter
   
 
subscribe
 
cancel

On Home Page         

LATEST

  • Meet­ing on­line may lead to hap­pier mar­riages

  • Pov­erty re­duction, environ­mental safe­guards go hand in hand: UN re­port

EXCLUSIVES

  • Was black­mail essen­tial for marr­iage to evolve?

  • Plu­to has even cold­er “twin” of sim­ilar size, studies find

  • Could simple an­ger have taught people to coop­erate?

  • Diff­erent cul­tures’ mu­sic matches their spe­ech styles, study finds

MORE NEWS

  • F­rog said to de­scribe its home through song

  • Even r­ats will lend a help­ing paw: study

  • D­rug may undo aging-assoc­iated brain changes in ani­mals

NASA’s Cassini spacecraft detected a surprising organic “brew” erupting like a geyser from Saturn’s moon Enceladus during a close flyby on March 12, researchers say. Scientists think the moon may also have liquid water, which along with the organic chemicals and other features already found could provide most of the prerequisites for life. Investigators in the Cassini mission described themselves as amazed that this tiny moon is so active, “hot” and brimming with water vapor and organics. New heat maps of the surface show higher temperatures than previously known in the south polar region, with hot tracks running the length of giant fissures. Additionally, scientists say the organics “taste and smell” like some of those in comets. A big surprise “is that the chemistry of Enceladus, what’s coming out from inside, resembles that of a comet,” said Cassini team member Hunter Waite of the Southwest Research Institute in San Antonio, Texas. “To have primordial material coming out from inside a Saturn moon raises many questions on the formation of the Saturn system.” “Enceladus is by no means a comet,” he added. Its activity “is powered by internal heat while comet activity is powered by sunlight. Enceladus’ brew is like carbonated water with an essence of natural gas.” The Cassini instrument for which Waite is principal investigator, the Ion and Neutral Mass Spectrometer, saw a much higher density of volatile gases, water vapor, carbon dioxide and carbon monoxide, as well as organic materials, some 20 times denser than expected. This dramatic increase in density was evident as the spacecraft flew over the area of the plumes. New heat maps of the south pole show that the so-called tiger stripes, giant fissures that are the source of the geysers, are warm along almost their entire lengths, researchers said. These more precise new measurements reveal temperatures of at least minus 135 degrees Fahrenheit. The warmest regions along the tiger stripes correspond to two of the jet locations seen in Cassini images. “These spectacular new data will really help us understand what powers the geysers. The surprisingly high temperatures make it more likely that there’s liquid water not far below the surface,” said John Spencer, Cassini scientist at the Southwest Research Institute in Boulder, Colo. The jets blast off the surface into space. “Enceladus has got warmth, water and organic chemicals, some of the essential building blocks needed for life,” said Dennis Matson, Cassini project scientist at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “We have quite a recipe for life on our hands, but we have yet to find the final ingredient, liquid water, but Enceladus is only whetting our appetites for more.” Scientists are hoping that microbial life might turn out to exist in a wet interior of the moon, though other factors, such as a lack of sunlight, could make that difficult. Cassini came within 30 miles (48 km) of Enceladus, researchers said. When it flew through the plumes it was 120 miles (190 km) away. An additional flyby is scheduled for August.