More Moons Around Pluto? Options

[JRehling]

Press Release Source: NASA


NASA's Hubble Reveals Possible New Moons Around Pluto
Monday October 31, 12:30 pm ET


WASHINGTON, Oct. 31 /PRNewswire/ -- Using NASA's Hubble Space Telescope to view the ninth planet in our solar system, astronomers discovered Pluto may have not one, but three moons.
If confirmed, the discovery of the two new moons could offer insights into the nature and evolution of the Pluto system; Kuiper Belt Objects with satellite systems; and the early Kuiper Belt. The Kuiper Belt is a vast region of icy, rocky bodies beyond Neptune's orbit.

"If, as our new Hubble images indicate, Pluto has not one, but two or three moons, it will become the first body in the Kuiper Belt known to have more than one satellite," said Hal Weaver of the Johns Hopkins Applied Physics Laboratory, Laurel, Md. He is co-leader of the team that made the discovery.

Pluto was discovered in 1930. Charon, Pluto's only confirmed moon, was discovered by ground-based observers in 1978. The planet resides about 3 billion miles from the sun in the heart of the Kuiper Belt.

"Our result suggests other bodies in the Kuiper Belt may have more than one moon. It also means planetary scientists will have to take these new moons into account when modeling the formation of the Pluto system," said Alan Stern of the Southwest Research Institute, Boulder, Colo. Stern was co-leader of the research team.

The candidate moons, provisionally designated S/2005 P1 and S/2005 P2, were observed approximately 27,000 miles away from Pluto. The objects are roughly two to three times as far from Pluto as Charon.

The team plans to make follow-up Hubble observations in February to confirm the newly discovered objects are truly Pluto's moons. Only after confirmation will the International Astronomical Union consider names for S/2005 P1 and S/2005 P2.

The Hubble's Advanced Camera for Surveys observed the two new candidate moons on May 15, 2005. The candidates are roughly 5,000 times fainter than Pluto. Three days later, Hubble looked at Pluto again. The two objects were still there and appeared to be moving in orbit around Pluto.

The team looked long and hard for other potential moons around Pluto. "These Hubble images represent the most sensitive search yet for objects around Pluto," said team member Andrew Steffl of the Southwest Research Institute. "It is unlikely that there are any other moons larger than about 10 miles across in the Pluto system," he said.

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. The Space Telescope Science Institute in Baltimore conducts Hubble science operations. The Institute is operated for NASA by the Association of Universities for Research in Astronomy, Inc., Washington.


For detailed information and images about this research on the Web, visit:

http://hubblesite.org/news/2005/19

For information about NASA and agency programs on the Web, visit:

http://www.nasa.gov/home




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Source: NASA

[Gsnorgathon]

All this talk of resonance and opposition surges makes me wonder - are the masses of the two moons enough to result in any geological activity on any of the four bodies in the Pluto system?

I'm also wondering - I know the new moons were imaged in 2002; is there any chance that they show up in any of the data from the 1985 - 1990 Pluto/Charon mutual occulatations? My first guess is they'd be buried in the noise, but hope springs eternal.

[tasp]

All this talk of resonance and opposition surges makes me wonder - are the masses of the two moons enough to result in any geological activity on any of the four bodies in..... (sorry zorched the quote, T)

Wow! What a good question!

Pluto and Charon are known to have differing surface compositions, Pluto more methane, Charon more water ice.

Consider Io, depleted of light elements, presumably from tidal heating effects.

And now we are looking at Charon, seemingly depleted of a more volatile compound compared to nearby Pluto.

Seems reasonable that by what ever process created Charon, it was not in tide lock at inception. As Pluto and Charon tidally interacted, power dissapated in Charon 'boiled' off the methane. Also, I think Charon would have receded from Pluto while this was occuring (Pluto not tide locked to Charon at that time either, and it would have accelerated Charon in its orbit as earth is doing to our moon even now). While Charon is receding from Pluto, its' resonances will move outward with it and "snag" outer satellites as we now observe.

All this seems to fit together, resonant orbits, tide locking, tidal recession, and surface chemistry.

That was a really good question, Gsnorgathon.

[tasp]

Additional:

Perhaps the Io analogy needs to be pressed a little further. A tidal effect sufficient to 'demethanize' Charon should leave a lasting relic on the presumably now permanently frozen surface.

The phrase 'widespread and recurrent {methane} volcanism' in regards to Charon springs to mind. Once the tidal effects died down, Charon would have froze up and preserved the geological manifestations of this period.

Geysers or volcanoes? Tar pits or artesian springs?

What would such a modified object look like?