Cassini Finds Atmosphere on Enceladus

[odysseus145]

Cassini finds Saturn moon Enceladus has an atmosphere, NASA says<br /><br />PASADENA, Calif. - The international Cassini spacecraft has discovered that Saturn's moon Enceladus has a significant atmosphere, NASA said Wednesday.<br /><br />The icy moon's atmosphere may be created by volcanism, geysers or gases escaping from the surface or the interior, the space agency's Jet Propulsion Laboratory said.<br /><br />Excluding Saturn's giant moon Titan, which was already known to have an atmosphere, it's the first discovery of an atmosphere on one of the more than 30 moons that orbit the ringed planet.<br /><br />Since reaching Saturn last summer, Cassini has made two close flybys of Enceladus, the shiniest object in the solar system.<br /><br />The finding was made through use of Cassini's magnetometer instrument during a Feb. 17 pass at an altitude of 725 miles of Enceladus' surface and a March 9 approach to within 310 miles.<br /><br />The instrument's observations included detection of magnetic field oscillations caused by interactions with electrically charged, or ionized, molecules. Because the frequencies of the oscillations can be used to identify the molecule, scientists believe the Enceladus observations were due to ionized water vapor.<br /><br />"These new results from Cassini may be the first evidence of gases originating either from the surface or possibly from the interior of Enceladus," Michele Dougherty, principal investigator for the Cassini magnetometer and professor at Imperial College in London, said in a statement.<br /><br />Since Enceladus is a relatively small moon - 310 miles in diameter - and the gravity it exerts is not enough to hold an atmosphere for very long, there must be a strong continuous source to maintain an atmosphere, NASA said.<br /><br />Such a source could be eruptions from volcanoes or geysers, which would put Encel <div class="Discussion_UserSignature"> </div>

 

[odysseus145]

Release from JPL <div class="Discussion_UserSignature"> </div>

 

[vogon13]

Bravo! Magnificent! Excellent!<br /><br />Might be another one lurking around another of the smaller moons............. <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[CalliArcale]

This is very exciting news. Not only does it bolster suspicions about the source of the E ring, but it also may be part of the puzzle for determining how Enceladus got to be so bright and shiny. It has a very young surface. If there is some sort of ice volcanism going on, it would explain Enceladus' surface, its rarified atmosphere, and the E-ring all in one go. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[vogon13]

Before Cassini reached Saturn, like maybe around Jan. 2004, Cassini detected major changes in E-ring. This has got be relevent. <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[yurkin]

I would sure like to see an Enceladus geyser shooting off. <br />I wonder though why does Enceladus appear to be active and other larger moons of Saturn appear to not be? <br /><br /><font color="yellow"> Cassini detected major changes in E-ring.</font><br />An eruption maybe?<br />

 

[CalliArcale]

<blockquote><font class="small">In reply to:</font><hr /><p>I wonder though why does Enceladus appear to be active and other larger moons of Saturn appear to not be?<p><hr /></p></p></blockquote><br /><br />If it helps, scientists strongly suspect Titan to be geologically active too. <img src="/images/icons/wink.gif" /> <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>

 

[chew_on_this]

I think tidal influence is a large part of it. If the moon isn't being pulled or tugged by other bodies, no internal geological heat is generated.

 

[meteo]

Has anybody heard how much atmosphere there is?<br />

 

[vogon13]

Not enough for a helicopter. <div class="Discussion_UserSignature"> <p><font color="#ff0000"><strong>TPTB went to Dallas and all I got was Plucked !!</strong></font></p><p><font color="#339966"><strong>So many people, so few recipes !!</strong></font></p><p><font color="#0000ff"><strong>Let's clean up this stinkhole !!</strong></font> </p> </div>

 

[5stone10]

<font color="yellow">how much atmosphere there is</font><br /><br />Judging by the lousy JPL graphic - its greater than the circumference of Saturn including the rings !!

 

[CalliArcale]

I don't have time to create an account at MercuryNews, so I don't know for sure what JPL graphic you're referring to, but it's probably noting how Enceladus is believed to feed the E ring (which is very large indeed, and extremely diffuse -- sort of like Jupiter's Diaphanous Ring).<br /><br />Click here for a very good graphic of Saturn's ring system, including the E ring <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em>  -- The Tenth Doctor, "Blink"</font></p> </div>