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ceejayoz • today at 4:09 PM • 2 replies • view on HN

They’re far enough out that they can see some stuff you don’t see from Earth. They aren’t seeing the entire far side yet.

Illustrated: https://www.reddit.com/r/Astronomy/comments/1sd797j/the_moon...

Replies

gus_massa • today at 4:53 PM

It got deleted now. It would be nice to see a new versions if abailable.

So, let's make some guess, but IANAA. Orion is in the middle of the trip going to the meeting point to the Moon in a quite straight line but the Moon is still not there. It will be there in 2 or 3 days, that is like 45° of the orbit.

  O                                                          .   .    o
  Earth                            >   .    .     .     .             Moon
                                   Orion                              in 3 days
                                                                    .
                                                                  .
                                                               .
                                                            .
                                                         .
                                                       .
                                                     o
                                                     Moon
                                                     now
Using some sloppy Math and sloppy Astronomy, I estimate that the difference between our point of view and their point of view is 20° or 30°. So the visible surface has like a 10% difference, that is consistent to call it a "glimpse". My estimation is also similar to the graphic posted in Reddit, but I'm not sure what was the problem.

I actually can't tell the difference in the photo to save my life, but I have a friend that is astronomer and I'm sure that if I show the photo to him, he could use a sharpie to mark the difference on my screen without any problem.

➕ show 1 reply
runjake • today at 4:20 PM

Hence the use of first glimpse.