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Comment by herodotus | Hacker News Reader

I am curious. If it is on the far side, where does the light come from for the photos? Other stars?

The moon is tidally locked with the Earth, which means the same side always faces the Earth. So, for example, when the moon is between the Earth and the sun, the far side (from the perspective of Earth) would be fully illuminated by the sun.

The “far side” of the moon refers to the hemisphere that can’t be seen from Earth.

Yes, and right now is full moon, thus the far side is only illuminated by stars.

I wonder why they decided on that timing? If it were better illuminated by the sun, couldn't they get some better photography?

They want to fly by at lunar sunrise as the shadows help see depth better. Also, they have very sensitive cameras (up to 3,280,000 ISO!); the Earth photo the other day was taken at night, so you can see how they'll be able to get detail even in the dark parts

640 ISO ought to be enough for anyone.

My guess is that this mission is not about imaging the far side of the Moon at all as that has been done already.

Fair, but these images are going to get a lot of public attention, so making them good ones would be worthwhile.

current 2nd stage is underpowered, so it has to be compensated by 1st stage right from the start

and since launchpad is in the north hemisphere, Moon has to be at the south part of its orbit

This is a vehicle test, not a sightseeing trip. Photography is not the priority.

The social media team.

And a little bit by asteroids like 20 Massalia and comets like 24P/Schaumasse.

It isn't full right now. It's a waning gibbous, so the far side is a waxing crescent.

Well, mathematically full moon is only a infinitesimally small split of a second. When I made the comment it was about 12% waxing crescent thus 88% in the dark. And actually darker than a full moon because the earth does not light up the far side.

The sun. The moon always shows the same side to Earth, so the far side has phases just like the Earth-facing side does. When we see a full moon from Earth, the far side is a "new moon"; when we see a new moon, the far side is full. And so on for the other lunar phases.

The sun still. It's just that that side never points towards the earth, but it still gets sunlight. Same as how the side we see isn't fully lit except during a full moon.

The other well publicized photo they did was of the dark side of the earth (it was night), so same idea(?)

The sun

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