Two more moons discovered orbiting Pluto

[Philotas]

Two more moons, S/2005 P1 and S/2005 P2, both between 45 to 160 kilometers in diameter have been discovered orbiting Pluto.<br /><br /><br /><font color="yellow">Preliminary observations suggest they are in circular orbits around Pluto and in the same plane as Charon, said Hal Weaver of the Johns Hopkins Applied Physics Laboratory.<br />"That suggests they probably formed at the same time as Charon," Weaver told SPACE.com. </font><br /><br />Two more interesting photo opportunities for New Horizons now. <img src="/images/icons/smile.gif" /><br /><br /><br /><br />Article: http://www.space.com/scienceastronomy/051031_pluto_moons.html <div class="Discussion_UserSignature"> </div>

 

[CalliArcale]

My jaw has just dropped open!<br /><br />Two new moons around Pluto? COOL!!!!! Wow, that's....not something I was expecting ever to hear about! Neato! That is incredibly cool.<br /><br />Personally, I don't think it's really weird that something smaller than the Moon could have satellites. Heck, puny little Ida has a satellite, so why not? It disturbs common sense, but not physics. <img src="/images/icons/wink.gif" /><br /><br />Thanks very much for calling attention to this article. I don't know how I missed it before, but that is incredibly cool! <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>

 

[drwayne]

Its interesting to me because smaller bodies (like our moon for example) tend to have inhomogenius distributions, which mess with orbits quite badly.<br /><br />Wayne <div class="Discussion_UserSignature"> <p>"1) Give no quarter; 2) Take no prisoners; 3) Sink everything."  Admiral Jackie Fisher</p> </div>

 

[volcanopele2]

87 Sylvia is only 384×264×232 km yet it has two satellites, Romulus and Remus:<br /><br />http://en.wikipedia.org/wiki/87_Sylvia

 

[vogon13]

Imagine my surprise.<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]

Found some estimates for periods of revolution of these two new birds. The outer is around 38.4 days and the inner is 25.5 days. Periods, at this point are very rough, although there does appear to be a 'prediscovery' Hubble picture from 3 years ago, which when analyzed, should help pin down the periods quite a bit. <br /><br />I did the math, and these periods divide out quite close to 4:1 and 6:1 resonance with Charon.<br /><br />Interesting!<br /><br /><img src="/images/icons/wink.gif" /><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>

 

[jmilsom]

The Boulder South West Research Institute Site has excellent and detailed background information on this recent discovery.<br /><br /> LINK <div class="Discussion_UserSignature"> </div>

 

[vogon13]

<img src="/images/icons/wink.gif" /><br /><br />That's where I found the periods of revolution estimates.<br /><br />Assuming the objects to be in resonance with Charon, the periods would be 25.548 days and 38.322 days. I'm not sure we will know till New Horizions arrives whether either or both objects are tide locked to Pluto. Surface brightness variations causing enough light curve to figure a rotation period at 23 magnitude and near month long possible periods would make for a hard task, even with Hubble's full attention.<br /><br />Amazing, amazing discovery.<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]

I am not aware of any other 3 body (non-Trojan) resonant relationships except for Io, Europa and Ganymede, 1:2:4.<br /><br />These objects, Charon, P2 and P1, 1:4:6.<br /><br />Interesting if its true.<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]

Just for fun, played with Romulus and Remus a little bit.<br /><br />They seem close to a 3:8 relationship in orbital periods. Seems like that one applies some where else, too.<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]

Going out on a limb a little further,<br /><br />That Pluto and Charon are mutually tide locked in a period of 6.387 days ( both revolution and rotation, by the way ) seems to imply a period in the past where they were tidally interacting towards that state. As Charon climbed outwards from Pluto towards tide lock, its 'mathematical' resonances exterior to it would have also climbed accordingly, and probably snagged the closer satellite first, then as those two objects continued 'onward and upward', they (I'm saying 'they', but the primary object per the most effect is Charon) would have then snagged the outer object, and then all three would have moved outwards till the process arrested when Pluto and Charon tide locked to each other.<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>

 

[brellis]

I heard they've already gone back to some older Hubble pics and spotted them as part of confirmation. If Pluto is a 'minor' planet, I guess they're 'minor' moons <img src="/images/icons/smile.gif" /> <div class="Discussion_UserSignature"> <p><font size="2" color="#ff0000"><em><strong>I'm a recovering optimist - things could be better.</strong></em></font> </p> </div>

 

[mattblack]

This is SERIOUSLY cool!! Another strong reason for doing one final Service/Upgrade mission. <div class="Discussion_UserSignature"> <p> </p><p>One Percent of Federal Funding For Space: America <strong><em><u>CAN</u></em></strong> Afford it!!  LEO is a <strong><em>Prison</em></strong> -- It's time for a <em><strong>JAILBREAK</strong></em>!!</p> </div>

 

[vogon13]

I noted that methane ice is conspicously absent from the surface of Charon and present on Pluto. Odd perhaps that two nearby objects would be so different, unless.......<br /><br />Charon dissipated tidal energy while its orbit was enlarging around Pluto sufficiently fast to 'process' Charon enough to 'bake off' the volatile methane.<br /><br />Perhaps a volatile depleted Charon is just a logical consequence of a past characterized by tidal interactions with Pluto. That 2 outer satellites may have been 'snagged' during the tidal evolution of the Pluto/Charon system may be viewed as further confirmation of the scenario.<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]

Small bodies with satellites?<br /><br />Goodness! I have been thinking Polydueces, Calypso, Helene, Telesto, and Hyperion are 'lost' satellites of several moons, and that several such objects are yet to be fathomed out. <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]

Its amazing how the more we know the more we can figure out. And once more stuff is figured out, then there is more stuff, seemingly mysterious before, that becomes understandable.<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]

In my opinion, that is by far the absolute coolest thing about science. <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>

 

[vogon13]

We be in hawg heaven, so to speak.<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>

 

[mikeemmert]

Very interesting. I suppose now that 2003 EL61 and 2003 UB313 will get Hubble time? The mechanical difficulties with Hubble and the new interest in the definition of the word, "planet" would seem to prioritize these observations. As your link noted, Pluto will be too close to the Sun to observe with Hubble until February. 2003 UB313 should be observable, though.<br /><br />We need a couple of more space telescopes, including some more capable infrared equipment. Spitzer's a fine instrument, but there's only so much capability that can be loaded aboard a dinky little Delta II rocket and fired to Earth escape velocity (to get away from Earth's infrared glare with it's heating and the loss of [hydrogen] ice).<br /><br />Too bad Spitzer didn't see 2003 UB313. I'll bet anybody a dollar to a doughnut that the mass of 2003 UB313 is within 20% of Triton's.

 

[vogon13]

The outer solar system ('round Pluto) is a pretty 'smooth' area, gravity wise. Pluto's closest 'big' neighbor, Uranus (yeah, the resonance with Neptune keeps Neptune and Pluto further apart, Pluto sneaks closer to Uranus at longish intervals) isn't really close enough at all to put much of a tidal effect at that distance.<br /><br />That there are objects floating around out there larger than Pluto probably doesn't matter too much, close approaches to other objects would be quite rare, and a passing snowball with a tiny fraction of our moon's mass isn't going to affect much of anything unless they collide.<br /><br />Note, some of those objects are also in resonant relationships with Neptune also, and close approaches amongst them would be of less consequence as the 'course corrective' nature of the effect the Neptune resonance would help them'hold their ground'.<br /><br />That Pluto has several satellites is perhaps less surprising if consideration is given to that Jupiter in closer proximity to Saturn and solar perturbations managed a nice satellite system. That Pluto could too, way out and 'undisturbed' where it is, maybe isn't so surprising.<br /><br />I will admit to some curiousity about material in a Trojan relationship with Charon now. Lack of disturbing influences implies a nice parking space 60 degrees ahead and behind Charon.<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]

As the satellites of, for example, Jupiter and Saturn, are believed to have been formed simultaneously with their host planets, and earth's moon is believed to have been collosionally generated soon after earth's primary accretion, so too Pluto/Charon are believed to have formed in a manner more similar to earth than Jupiter.<br /><br />--BUT--<br /><br />Now I'm not so sure.<br /><br />That some trans Neptunian objects formed satellites via either process seems reasonable, but discerning which object goes in which categaory, I just don't think we know enough now.<br /><br /><br />{oops, I'm messing with Cali's progression of science, I found out something new and now I want to throw a flag on the play}<br /><br /><br />{btw, I never use sports metaphors, and therefore, have just auto-diagnosed a brain tumor <img src="/images/icons/wink.gif" />}<br /><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>

 

[mpai]

With the barry centre of Charon being above the surface of Pluto, makes them both a kind of a "double planet". It will now be interesting to observe if this two satellites are acutally the satellites of Pluto or Charon or of both.

 

[vogon13]

Barycenter nevertheless, is quite close to Pluto. New moons orbit the barycenter of the whole system, of course, as do Pluto and Charon.<br /><br />I hereby grant special and ordinary dispensation to everyone to say three moons orbit Pluto, those who know the difference will smile inward smuggly, and the rest of the proles get to maintain their happy uncomplicated lives.<br /><br /><img src="/images/icons/wink.gif" /><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>