Pluto moon Charon ping
“Charon, also called (134340) Pluto I,[1] is the largest of the five known moons of the dwarf planet Pluto. It was discovered in 1978 at the United States Naval Observatory in Washington, D.C., using photographic plates taken at the United States Naval Observatory Flagstaff Station (NOFS). It is a very large moon in comparison to its parent body, Pluto. Its gravitational influence is such that the barycenter of the Pluto–Charon system lies outside Pluto.
New Horizons flew through the Pluto–Charon system on 14 July 2015, approaching to within 27,000 km (17,000 mi) of Charon.”
https://en.wikipedia.org/wiki/Charon_%28moon%29
Alex Trebek keeps saying there are now only 8 planets.
Who gets to decide? I think Pluto clearly is a planet.
“Charon and Pluto orbit each other every 6.387 days. The two objects are gravitationally locked to one another, so each keeps the same face towards the other. This is a case of mutual tidal locking, as compared to that of the Earth and the Moon, where the Moon always shows the same face to Earth, but not vice versa. The average distance between Charon and Pluto is 19,570 kilometres (12,160 mi).
The discovery of Charon allowed astronomers to accurately calculate the mass of the Plutonian system, and mutual occultations revealed their sizes. However, neither indicated the two bodies’ individual masses, which could only be estimated, until the discovery of Pluto’s outer moons in late 2005. Details in the orbits of the outer moons reveal that Charon has approximately 11.65% of the mass of Pluto.[3] This shows it to have a density of 1.65 ± 0.06 g/cm3, suggesting a composition of 55 ± 5% rock to 45% ice, whereas Pluto is somewhat denser and about 70% rock.
Simulation work published in 2005 by Robin Canup suggested that Charon could have been formed by a collision around 4.5 billion years ago, much like Earth and the Moon. In this model, a large Kuiper belt object struck Pluto at high velocity, destroying itself and blasting off much of Pluto’s outer mantle, and Charon coalesced from the debris.[21]
However, such an impact should result in an icier Charon and rockier Pluto than scientists have found. It is now thought that Pluto and Charon may have been two bodies that collided before going into orbit about each other. The collision would have been violent enough to boil off volatile ices like methane (CH4) but not violent enough to have destroyed either body.”
https://en.wikipedia.org/wiki/Charon_%28moon%29
I wonder if Pluto calls his little moon, ‘My Charona’?... (Sorry, as he slinks off to another thread).
Charon (Geology)
“Charon’s diameter is 1,208 kilometres (751 mi)—just over half that of Pluto,[26] and larger than the dwarf planet Ceres. Charon is sufficiently massive to have collapsed into a spheroid under its own gravity. Unlike Pluto’s surface, which is composed of nitrogen and methane ices, Charon’s surface appears to be dominated by the less volatile water ice. In 2007, observations by the Gemini Observatory of patches of ammonia hydrates and water crystals on the surface of Charon suggested the presence of active cryogeysers and cryovolcanoes.[27][28]
Charon’s volume and mass allow calculation of its density, from which it can be determined that Charon is slightly less dense than Pluto and thus contains a larger proportion of ice relative to rock in its interior; the difference is considerably lower than that of most suspected collisional satellites. Before New Horizons’ flyby, there were two conflicting theories about Charon’s internal structure: some scientists thought Charon to be a differentiated body like Pluto, with a rocky core and an icy mantle, whereas others thought it would be uniform throughout. Evidence in support of the former position was found in 2007, when observations by the Gemini Observatory of patches of ammonia hydrates and water crystals on the surface of Charon suggested the presence of active cryogeysers. The fact that the ice was still in crystalline form suggested it had been deposited recently, because solar radiation would have degraded it to an amorphous state after roughly thirty thousand years.[27]
Photometric mapping of Charon’s surface shows a latitudinal trend in albedo, with a bright equator band and darker poles. The south polar region is apparently darker than the north.[29] The north polar region is dominated by a very large dark area informally dubbed “Mordor” by the New Horizons team.[30][31][32] Aside from Mordor, however, New Horizons imaged very few other impact craters on Charon and found a youthful surface, adding support to the above theory that Charon is geologically active and thus probably differentiated.[31] In particular, the southern hemisphere has fewer craters than the northern and is considerably less rugged, suggesting that a massive resurfacing event—perhaps prompted by the partial or complete freezing of an internal ocean—occurred at some point in the past and removed many of the earlier craters.[33]
https://en.wikipedia.org/wiki/Charon_%28moon%29#Geology
It looks like it was painted by Jackson Pollock.
Cool (probably very cool). Thanks for posting and FReeper humor.
Wait, don’t you have to be a planet to have a moon?
How do we know this picture wasn’t taken by Stanley Kubrick on a London filmstage in the late 60s? I don’t see any stars.
Here the petition to promote Pluto back to planetary status…
Remember you are not just helping Pluto but if it was promoted it would be a stick in the eye of atheist activist Neil Tyson’s who played a big role in demoting it.
https://www.change.org/p/international-astronomical-union-declare-pluto-a-planet-plutoflyby