Pluto might have rings?

[mikeemmert]

Howdy, folks;<br /><br />This article in Space.com is about the confirmation of Pluto's new moons by the Hubble Space telescope . They're there, all right.<br /><br />But the Space.com article expands on that theme by speculating that there might possibly be rings around Pluto. There is nothing in the photos or data to indicate that, nor should any such thing be expected.<br /><br />Rings closer to Pluto than Charon would seem to me to be rather unlikely because of atmospheric drag. While Pluto's atmosphere is transient, it doesn't take a persistent atmosphere to drag the rings down. An occasional puff will do.<br /><br />It has been noted elsewhere that Charon has no atmosphere. Since Charon is so close, might it be reasonable to assume that if Pluto's atmosphere got as high as the rings, that some might spill over onto Charon?<br /><br />The problem here is that Charon is considerably darker than Pluto, absorbing almost twice as much solar energy. Therefore any atmosphere that spills over onto it would be evaporated and driven off.<br /><br />The article also mentions ring arcs. One could imagine them in the Pluto/Charon L4 and L5 points. But <i>Pluto has no Lagrange points</i>. For those to occur, Pluto would have to be at least 24.96 times the size of Charon . But it's only about 8 times the mass of Charon.<br /><br />Could there be rings outside of Charon? Maybe. But it seems they would have coalesced into moons, like P1 and P2.<br /><br />I guess we'll all find out when New Horizons reaches Pluto!

 

[yevaud]

There is already an active thread on this subject: "Pluto: Rings?" in Ask the Astronomer. <div class="Discussion_UserSignature"> <p><em>Differential Diagnosis:  </em>"<strong><em>I am both amused and annoyed that you think I should be less stubborn than you are</em></strong>."<br /> </p> </div>