4 ms·

It’s far side, not dark side. The moon doesn’t have a dark side anymore than the earth does

wumms 8mo ago
NASA uses "dark side" (meaning far side, not night side) when facing the public [0]: > A series of test images shows the fully illuminated “dark side” of the Moon that is not visible from Earth. > The far side of the Moon was first observed in 1959 [0] https://science.nasa.gov/earth/earth-observatory/the-dark-side-and-the-bright-side-86353 https://science.nasa.gov/earth/earth-observatory/the-dark-si...
- KineticLensman 8mo ago
  > the fully illuminated “dark side” Personally, I don't find the phrase 'fully illuminated “dark side”' to be a convincing alternative to the physically more accurate term 'far side'. Of course NASA has only just emerged from the Earth's dark side as I write this (UK here, mid-morning), so I'm not expecting an immediate response from them. And yes, I do know that 'side' is itself not entirely accurate because of libration [0] but that's a different hill to die on. [0] https://en.wikipedia.org/wiki/Libration#Lunar_libration https://en.wikipedia.org/wiki/Libration#Lunar_libration
  - wumms 8mo ago
    Agreed. The far side is the darker side, though, at lunar night. Poetic proof: "The Earth shine might illuminate the light side of the Moon a little during the long night" (from Jules Verne, All Around the Moon https://www.gutenberg.org/cache/epub/16457/pg16457-images.html https://www.gutenberg.org/cache/epub/16457/pg16457-images.ht...)
    - KineticLensman 8mo ago
      I do like poetry, but if we are looking at a crescent moon, in our night, it means that the bulk of farside is facing toward the sun, and will therefore be brighter than nearside
      - wumms 8mo ago
        This describes lunar day on the far side of the moon, right? Excuse my ambiguity; I was comparing lunar nights only (inspired by the Jules Verne quote): The far side is darker during lunar night (lit by starshine only; Full Moon on Earth) than the near side during lunar night (New Moon on Earth), because it receives both star- and max. Earthshine. I'm not sure about Crescent Moon though: that only narrows the brightness gap slightly, right? Or I’ll have to ask if there’s an astronomer on board our flight.
- rbanffy 8mo ago
  > NASA uses "dark side" (meaning far side, not night side) when facing the public [0]: That's not helpful, at all.
perilunar 8mo ago
Well the point is it needs to be both. The telescope needs to be on the far side to shield it from Earth, and the dark side to shield it from the Sun. But yes, it's only on the dark side 50% of the time.
8bitsrule 8mo ago
For 14 days a month, it's the dark side. That's the whole idea. Astronomy 101.

wumms 8mo ago

NASA uses "dark side" (meaning far side, not night side) when facing the public [0]: > A series of test images shows the fully illuminated “dark side” of the Moon that is not visible from Earth. > The far side of the Moon was first observed in 1959 [0] https://science.nasa.gov/earth/earth-observatory/the-dark-side-and-the-bright-side-86353 https://science.nasa.gov/earth/earth-observatory/the-dark-si...

KineticLensman 8mo ago
> the fully illuminated “dark side” Personally, I don't find the phrase 'fully illuminated “dark side”' to be a convincing alternative to the physically more accurate term 'far side'. Of course NASA has only just emerged from the Earth's dark side as I write this (UK here, mid-morning), so I'm not expecting an immediate response from them. And yes, I do know that 'side' is itself not entirely accurate because of libration [0] but that's a different hill to die on. [0] https://en.wikipedia.org/wiki/Libration#Lunar_libration https://en.wikipedia.org/wiki/Libration#Lunar_libration
- wumms 8mo ago
  Agreed. The far side is the darker side, though, at lunar night. Poetic proof: "The Earth shine might illuminate the light side of the Moon a little during the long night" (from Jules Verne, All Around the Moon https://www.gutenberg.org/cache/epub/16457/pg16457-images.html https://www.gutenberg.org/cache/epub/16457/pg16457-images.ht...)
  - KineticLensman 8mo ago
    I do like poetry, but if we are looking at a crescent moon, in our night, it means that the bulk of farside is facing toward the sun, and will therefore be brighter than nearside
    - wumms 8mo ago
      This describes lunar day on the far side of the moon, right? Excuse my ambiguity; I was comparing lunar nights only (inspired by the Jules Verne quote): The far side is darker during lunar night (lit by starshine only; Full Moon on Earth) than the near side during lunar night (New Moon on Earth), because it receives both star- and max. Earthshine. I'm not sure about Crescent Moon though: that only narrows the brightness gap slightly, right? Or I’ll have to ask if there’s an astronomer on board our flight.
rbanffy 8mo ago
> NASA uses "dark side" (meaning far side, not night side) when facing the public [0]: That's not helpful, at all.

perilunar 8mo ago

Well the point is it needs to be both. The telescope needs to be on the far side to shield it from Earth, and the dark side to shield it from the Sun. But yes, it's only on the dark side 50% of the time.

8bitsrule 8mo ago

For 14 days a month, it's the dark side. That's the whole idea. Astronomy 101.