1st Video of Moon's Far Side 118
chill writes "A gravity-mapping spacecraft orbiting the moon has beamed home its first video of the lunar far side — a view people on Earth never see. Because the moon is tidally locked with Earth, it only presents one face to the planet's surface (the near side). The side of the moon that faces away from Earth is the far side. Only robotic spacecraft and Apollo astronauts who orbited the moon in the 1960s and 1970s have seen the far side of the moon directly."
Re:Dark Side (Score:4, Informative)
Just in case you're not joking -- there is no dark side of the moon. At least, no permanent one -- of course, one side is dark at any moment, but it's constantly changing. The moon only presents one side to us earthlings, but all sides to the sun.
Re:Dark Side (Score:2, Informative)
Not first Video of the far side of the moon (Score:5, Informative)
Actually I'm almost positive that this is not the first video of the far side of the moon (and certainly not the first images, that was done by some Russian probe back in the 60s I think).
Not only did the aforementioned Apollo astronauts take moving images (ok, maybe not technically video) of the far side during their orbits but I recall that even the recent Japanese or Chinese lunar probes were transmitting hi-def videos including (I think) a beautiful "earth-rise". Which by definition means they had to be imaging at least part of the far side.
No, this is just the first video of the far side from GRAIL (which is pretty awesome regardless). Now there is a chance that due to the fact that GRAIL entails TWO spacecraft that one could be acting as a relay which would make this the first LIVE video from the far side. But considering the small separation distance of them (less than 100km?) I doubt it.
Re:Dark Side of the Moon (Score:5, Informative)
Looks like you never listened to Pink Floyd.
Re:Not first Video of the far side of the moon (Score:4, Informative)
NASA's GRAIL mission has beamed back its first video of the far side of the moon. The imagery was taken on Jan. 19 by the MoonKAM aboard the mission's "Ebb" spacecraft.
http://www.nasa.gov/mission_pages/grail/news/grail20120201.html [nasa.gov] (Emphasis added)
Re:Dark Side (Score:2, Informative)
True. The proper and clear way to phrase it is: The farther side of the moon as measured in a geocentric coordinate system.
Re:Noob Question (Score:4, Informative)
Yes, they are. Also, gravity (via tidal forces) ensures this will be case in the future as well, having caused it in the first place.
Re:Noob Question (Score:5, Informative)
We're tidally locked which means at this point it's most stable for the moon to always face us. If something caused the moon to speed up its rotation a little bit, for instance, tidal locking would force it to slow back down to get back perfectly in sync with Earth. Earth is headed down the same path. I can't remember how many millions or billions of years it'll take, but eventually the Moon will slow down Earth's rotation and Earth will be tidally locked to the Moon, such that the same side of Earth will always be towards the Moon.
Grrr. First by me doesn't mean first. (Score:5, Informative)
Here is a Clue : It's Grail's first video, not anything like the first video.
Never mind Luna 3 in 1959 (which was stills). Never mind Lunar Orbiter (stills) and Apollo (movies). Never mind that Clementine mapped the whole of the Far Side over a decade ago. What about Selene ? It had an HD camera, and sent back video of far side, including cool shots like this one [selene.jaxa.jp], of Malapert Mt and Shackleton Crater, at the Lunar South Pole, or this video [wn.com] of Tsiolkovsky Crater, deep into the Far Side. These videos are cool, and worth spending some time with.
Re:Dark Side (Score:5, Informative)
Um, not it actually looks quite different. The lunar maria (the dark spots) are much less common. Reason being that those were formed by lava flows on the surface, and you can imagine that if there's molten rock inside, it would be pulled (as expected) towards a big nearby gravity well - Earth in this case.