Posted on 07/22/2011 9:48:37 AM PDT by SunkenCiv
Explanation: Nix and Hydra were first introduced to human eyes in Hubble Space Telescope images from May 2005, as Pluto's second and third known moons. Now Hubble images have revealed a fourth satellite for the icy, dwarf planet. Provisionally designated P4, it completes an orbit of Pluto in about 31 days. Presently Pluto's smallest and dimmest known moon, P4 is estimated to be 13 to 34 kilometers across. The newly discovered satellite was first spotted in Hubble observations from June 28, and later confirmed in a follow-up on July 3 and July 18. These two panels are composites of both the short and long exposures that include brighter Pluto itself along with Pluto's largest moon Charon. Camera noise and image artifacts also show up in the long exposure segments. The Hubble observations were made while searching for faint rings around the distant world in support of NASA's New Horizons mission, set to fly by the Pluto system in 2015.
(Excerpt) Read more at 129.164.179.22 ...
[Credit: NASA, ESA, Mark Showalter (SETI Institute)]
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A “non planet” with at least 4 moons an a potential for rings.
Hmmm
4 moons, huh?
They should give back to Pluto it’s planetary ranking.
Well, Pluto’s a “dwarf planet” so I guess those moons are mini-me’s...
BTW: Is Charon in a retrograde orbit or is it whizzing along so as to complete 3/4 of a revolution in 5 days?
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"To Pluto And Far Beyond" By David H. Levy, Parade, January 15, 2006 -- We don't have a dictionary definition yet that includes all the contingencies. In the wake of the new discovery, however, the International Astronomical Union has set up a group to develop a workable definition of planet. For our part, in consultation with several experienced planetary astronomers, Parade offers this definition: A planet is a body large enough that, when it formed, it condensed under its own gravity to be shaped like a sphere. It orbits a star directly and is not a moon of another planet. |
They’re tidally locked, showing the same face to each other, with an orbital period of a bit more than six days (it sez here). Charon has a lot lower density which means it wasn’t formed at the same time and place as Pluto. Mike Brown (discoverer / co-discoverer of the larger Kuiper Belt Objects or KBOs) claims that one of those KBOs was formed in a large impact that also gave birth to Pluto and Charon.
Thanks!
Learn something new everyday.
Me too. :’)
Oh, and I screwed up, Mike Brown sez those were two different impact events. I had planned to post some stuff of his regarding the possibility of a Planet X, haven’t yet, but should probably check anyway, in case I’d posted it before. :’)
Planet X was confirmed in 1953. But there were some problems.
Totally agree.
I learned 9 planets, I’ll die knowing 9 planets...unless one is added.
I agree. I understand the logic of the decision, but Pluto should still be a planet if for no other reason than tradition and the great story of its discovery. Thank goodness they got the New Horizons mission off before Pluto was demoted!
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