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Pluto's 3 Moons and a Probe to Study Them
It doesn't come easy writes "For those of you keeping score, Pluto now officially has three moons, with more possibly to follow. The newfound moons orbit about 27,000 miles (44,000 kilometers) from Pluto, more than twice as far as Charon, Pluto's other satellite. They are 5,000 times dimmer than Charon. The moons were found using the Hubble Space Telescope. For now, Pluto is the only Kuiper Belt object known to have satellites. Some nice images of Pluto and its moons are included in links. Enjoy!" Relatedly IZ Reloaded writes "NASA says the Atlas 5 rocket that will carry the New Horizons Pluto probe has suffered slight damage thanks to Hurricane Wilma. New Scientist reports: "The Atlas 5 rocket stands within a construction hangar at Cape Canaveral Air Force Station on Florida's east coast. As Wilma rolled though the region on 24 October, fierce 122-kilometer-per-hour winds tore holes in the hangar's 83-meter-tall door and caused minor damage to the rocket inside.""
For now, Pluto is the only Kuiper Belt object known to have satellites.
My good friend UB313 would have to disagree.
There are actually several known KBOs with moons. Or was the submitter being overly litteral and meant multiple moons?
Unlike what the poster said, Pluto is not the only one with a moon.. html
Various other KBOs do, including Xena :
http://www.planetary.org/news/2005/xena_moon_1003
Pluto now officially has three moons
More like "four big asteroids are gravitating around each other beyond the orbit of Neptune".
"A door is what a dog is perpetually on the wrong side of" - Ogden Nash
Those aren't moons. Those are space stations.
Paul Grosfield - the quicker picker upper.
1) The impactor, known alternately as Orpheus or Theia, has been modeled to have been about the size of Mars, and to have hit Earth at a very oblique angle. 2) The absolute best evidence we have for the theory is that the moon has essentially no iron core. All the other terrestrial planets do. As it turns out, the comosition of the moon is remarkably similar to that of Earth's mantle (oxygen/silicon). It is theorized that most of Theia's core merged with our own. Earth's mean density is, if I recall, something on the order of 5500 kg/m^3. The moon has a mean density of something like 3300 kg/m^3. If you were to take out the Earth's iron/nickle core and replace it with mantle material, it would have a mean density similar to that of the moon. 3) As an astronomy minor and having taken planetary formation courses, I've never heard anything about carbonaceous chondrite cores forming the basic building blocks of planets. Carbon, counterintuitively, isn't even too abundant on Earth. Or anywhere else for that matter. Or rather, there certainly is a lot of it, but not compared to oxygen, silicon, iron, aluminum, etc. 4) You can't compare the models of planetary formation in the inner solar system to the outer. Not on a 1:1 basis. The outer planets are significantly larger than the inner because they formed past the frost line (about halfway through the asteroid belt). After this line, ice stays in crystalline form, allowing the rocky starts of the other planets to aggregate much more mass, both planetary and gaseous (the rocky core of Jupiter, at least, is probably about 20 times the size of Earth). With this much more mass, they can more easily capture smaller planetismals, which become moons. It would be far, far easier for a Jupiter to capture Luna than for Earth. 5) As alluded to in the beignning of this post, computer simulations have been done on both the capture and impact theories (including many variations of). The impact theory works. The capture does not. 6) That we have plate tectonics, significant ocean basins, etc, could also be construed as evidence for the giant impact theory. Venus has no moons, and there is little evidence that it ever underwent plate tectonics. The same goes for Mars, and I assume Mercury, though I am not sure on the latter. But the most important thing here is #2. That's the smoking gun.