Posted on 06/14/2015 6:05:27 AM PDT by Lonesome in Massachussets
Pluto and Charon orbit their mutual center of gravity, which lies between Pluto and Charon. In this processed video, Pluto's location is kept stationary. If the view were stabilized with respect to the fixed stars, Pluto and Charon would both appear to be moving. (Pluto, perhaps more like swaying or wobbling.)
Second, Pluto and Charon are the only two objects in the solar system known to be mutually tidally locked, which means they keep the same face towards each other as they orbit. (The moon is tidally locked to the earth, but the earth is not tidally locked to the moon.) So the period of rotation of Pluto is exactly equal to the orbital period of Charon. And vice-versa. Think about it.
Third. The GIF begins and ends with Charon at the 3:00 O'clock position. The discontinuity (my speculation) is probably due to the change is prospective caused by the motion of the camera towards the pair during the 6.4 days that one complete orbit takes. The spacecraft closed about 1/20 of distance between itself and Pluto during this period.
Fourth: It takes light (and radio waves) about nine hours to travel from New Horizons to earth.
bfl
Little over 12,000 miles between Pluto and Charon.
Never understood why they removed Pluto from Planetary status.
Oh, my bad...
5.56mm
Because there’s two other objects in the same neighborhood that equal or rival Pluto’s size. Plus more undiscovered.
BTW the Philae lander on the comet has made contact and is awake.
http://www.wsj.com/articles/earth-receives-signals-from-rosetta-mission-probe-philae-1434285408
So why not designate “them” planets rather than change the status of Pluto. It does meat the requirements of a planet does it not?
Its an academic argument that doesn’t really settle anything. Personally I would have left Pluto alone and given planet status to Ceres.
Because they could, and because doing so got some publicity.
Looking forward to seeing close up pictures of Pluto. I want to rent some place for my summer retreat.
bump
“Never understood why they removed Pluto from Planetary status.”
To prepare you to accept that all solar systems discovered so far seem to consist of large planets. All other objects seem to be escaped moons. Our system is no different.
We have four planets: Uranus, Neptune, Saturn, and Jupiter. All others, including Earth are not planets, but just escaped moons ...
An awfully long way to go for a fly-by. I would have hoped for orbit.
Make sure you have a good view of Charon. And the sun. Pluto’s artic circle is near its equator, so the midnight sun lasts almost all summer on Pluto. Pack a lot of underwear. Summer on Pluto is 60 years long.
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