Distant Methone flyby today, 10/29/05

[vogon13]

While a close (<10,000 km flyby) is still a year away, Cassini will pass roughly 10 times further from Methone today.<br /><br />Methone is quite small (<5 km) and orbits Saturn between Mimas and Enceladus. One Voyager image is all we knew about this object prior to Cassini's arrival.<br /><br />Many 'rocks' orbit Saturn in the outer reaches of the ring system, and outwards towards Mimas. Methone is a little different, in that it has an orbit entirely within the orbits of 2 'big name' satellites, Mimas and Enceladus. <br /><br />I can't find any info on its orbital period around Saturn, so I don't know if it is in any kind of a resonant orbit situation with any other object. Hopefully, many aspects of this interesting little 'rock' will be illumed soon.<br /><br />I haven't seen any speculation on this objects origins, but would suspect it would be one of these:<br /><br />* primordial object, formed and remained right where it was found<br /><br />* 'wandering' chunk of Mimas, never recoalesced with Mimas, after a possible Mimassian disruption event<br /><br />* 'lost' moon of either Mimas or Enceladus, spun off long ago by tidal effects. (would consider this unlikely for a Enceladus origination, and somewhat less unlikely for Mimas)<br /><br />* 'lost' Lagrangian object from ?<br /><br />* captured asteroid or comet<br /><br />* space station (this one is a jokey)<br /><br /><br />I'll watch for any pics that might turn up at JPL, and will keep you posted.<br /><br /> <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>

 

[vogon13]

Looks like Methone has a period around around Saturn of 24 hours. <br /><br />We can conclude that Methone is in a resonance with earth.<br /><br />{JOKE!}<br /><br />Seriously, dividing out Mimas period with 24 hours didn't really cause any bells to go off with me resonance wise, but I suspect the 24 hour period is not real precise.<br /><br />Additionally, I just noticed Pallene is also orbitng Saturn between Miamas and Enceladus. (too many 'rocks' to keep track of!)<br /><br />So there are two little weirdlings to ponder.<br /><br /> Edit-Pallene of course, not Helene {yoiks}<br /><br /> <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]

It may be impossible to get an accurate orbital period for Methone; many of these small satellites have peculiar orbits due to interactions with the larger satellites. <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]

You might be right. I had thought perhaps the JPL folks didn't know any one cared and just hadn't bothered to post the info.<br /><br />Should either intra-Encela-Mimian 'rock' be in a resonant orbit situation, though, the average period should come out pretty precisely after object is tracked a couple of years.<br /><br />I don't know if either object showed in the Cassini approach pictures.<br /><br />These rocks are fascinating. I had always thought one of the drawbacks to being on a specific 'big name' moon of Saturn would be that while you would get to see all the other moons against a back drop of Saturn and its' rings, you would never be able to also see the moon you are standing on so portrayed. Standing on these rocks, you could see all the moons known prior to Voyager/Pioneer encounters.<br /><br /> <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>