From the Moon to Earth in HD

Lucas123 writes "The Japan Space Agency's Kaguya spacecraft is currently orbiting the moon and its equipment is being tested in preparation for its real mission to map the moon with high-definition images later this month. Almost as an afterthought, the space craft has recreated one of the most memorable photos in the history of spaceflight — an Earth-rise from lunar orbit."

Earth doesn't move

[Dan East]

There's an interesting phenomenon that most people don't consider. Since the moon rotates about its axis at the same period as its orbit, the earth always appears at the same place in the sky when viewed from a given location on the surface of the moon (unless of course you were on the "dark" side of the moon).

That would be incredibly useful for navigation!

The article seemed to misstate this fact:
Since the moon's rotation matches the Earth's rotation of the sun, the Earth will always appear to be in the same spot if seen by an astronaut standing on the moon.

Doesn't that infer the moon's rotation is 365.25 days?

Dan East

IMAX

[corsec67]

IMAX [wikipedia.org], could be scanned at 10000 x 7000 pixels, which definitely qualifies as HD.
And we already have quite a bit of IMAX footage.

Re:Not in HD

[fbjon]

Yes, but those are still pics, nothing new there. This particular camera on Kaguya is 3CCD HD video, which is rather unusual to have in space.

Re:Not in HD

[PhantomHarlock]

I looked at the two screenshots. The spatial resolution at 1:1 isn't so hot on that camera, but hey it's orbiting the moon, so can't ask for much more right now. It will also look better in motion. Hopefully I can get the Discovery HD program somehow.

Comparing to the medium format still footage by Apollo's Bill Anders (Whom I've had the pleasure of briefly meeting when he was flying a P51 around here recently), Bill's photos are exposed more for the lunar surface than the earth. It appears that the white clouds of earth are overexposed when the moon is in correct exposure, at least in the one shot linked above. The HD camera probably has a comparable or a little less exposure leniency depending on whether the Apollo cameras used slide or negative film. (I think they were slide?)

The JAXA footage has the earth exposed nicely and the moon is out of peak range, with most features deep in a medium grey. This has an advantage of bringing out the contour features on the lunar surface better. Also, seeing the progression of sunrise really looks interesting with no atmosphere. Landing on the moon at the perpetual twilight line would give one unlimited time to walk around and frame the earth against numerous lunar features. With the enlarged size of the earth, it will take less telephoto length to capture it at a reasonable size in the frame.

--Mike

Re:Why is the Earth upside down?

[JrOldPhart]

Why would you consider North to be up?

You fail the Kahn test. You are thinking two dimensionally.

Up would be away from the nearest gravity source.

Re:Why is the Earth upside down?

[domanova]

That's actually very interesting. Rotate the picture (better, the movies) 180 so our north pole is 'up' and the whole thing looks different. You're not 'flying over'; you're 'skimming under' or some such. A quite different perception

HD?

[popo]

This isn't meant as a troll... The shots are indeed beautiful.
But I was a little disappointed by the categorization of "HD"

Those seemed like pretty 'standard def' to me...

Are there higher res shots somewhere else?