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This article "Earthshine Reflects Earth's Oceans And Continents From The Dark Side Of The Moon" indicates that the difference in reflection of light from the Earth’s land masses and oceans can be seen on the dark side of the moon.

Could that difference be seen by the human eye from the moon? Basically, did any Apollo astronaut, while on the moon's surface, indicate whether they could distinguish Earth's continents from oceans?

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    $\begingroup$ The question is weird, because what they (scientists) are trying to achieve, is like watching TV normally vs. looking at some object illuminated by the TV screen and trying to infer some properties of the TV picture from the distant object's color and brighness. Obviously, human eye can see what's on the screen (and on the Earth), but there is no way Apollo astronauts could distinguish the light coming from Earth continents and oceans by looking at the dark portion of the moon. $\endgroup$
    – szulat
    Commented Mar 17, 2020 at 3:52
  • $\begingroup$ @szulat I don't think a question's "weird" just because the answer is "no". If you do think the answer is "no", please present your answer down below with all applicable facts and evidence. Thanks! $\endgroup$
    – Asteroids With Wings
    Commented Mar 17, 2020 at 11:20
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    $\begingroup$ @szulat I'm not suggesting the astronauts can determine anything by looking at a dark portion of the moon. What I'm asking is could the astronauts standing on the moon have seen and distinguish between the oceans and continents, by the naked eye. $\endgroup$
    – Bob516
    Commented Mar 17, 2020 at 14:23
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    $\begingroup$ @Bob516 I suspect the confusion is because that's what the article you linked to is about: observing the brightness of the dark portion of the moon. Obviously looking directly at Earth while standing on the Moon would make distinguishing continents much easier. (Though the human eye is also probably much less precise than wherever instruments the researchers were using in that paper.) $\endgroup$
    – Ajedi32
    Commented Mar 17, 2020 at 16:17
  • $\begingroup$ @Ajedi32 I agree, the confusion is probably because of the article. $\endgroup$
    – Bob516
    Commented Mar 17, 2020 at 16:36

3 Answers 3

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Yes, according to Mike Collins (but from lunar orbit, not on the surface).

The earth as seen from this distance - nearly a quarter of a million miles - is an unforgettable sight.

To begin with, it looks tiny, the size of your thumbnail held at arm's length. It is mostly ocean and clouds, the blue and white dominating the brownish-green of jungles, mountains and plains. The only land mass that really stands out is the North African desert, especially the oxide-rich, reddish Atlas mountains.

From Collins, Liftoff, p. 12

This is an Apollo 16 orbital picture of the CM and Earth from the LM.

enter image description here

Photo credit: NASA

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    $\begingroup$ I'm wondering if Collins would've had an easier time viewing the earth from the cm, compared to the two on the surface of the earth. Would the light reflected off the lunar surface made it more difficult for those on the surface to see the distinctions of the oceans and continents. That being said this was still a very useful answer. $\endgroup$
    – Bob516
    Commented Mar 17, 2020 at 2:49
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    $\begingroup$ It's possible, that's why I highlighted the part about being in orbit. Haven't found any quotes from a moon walker. $\endgroup$
    – Organic Marble
    Commented Mar 17, 2020 at 3:15
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I don't know if any Apollo astronaut talked about it, but in the famous "Earthrise" photo taken from lunar orbit on Apollo 8, landmass (the west coast of Africa, I believe, at the lower edge of the sunlit portion of Earth) is distinguishable from the oceans:

enter image description here

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    $\begingroup$ Is this photo zoomed in? I think the Earth is ~ 2 degrees wide to an observer on the Moon. $\endgroup$
    – Organic Marble
    Commented Mar 17, 2020 at 0:51
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    $\begingroup$ It's more like this: usgs.gov/media/images/… $\endgroup$
    – Organic Marble
    Commented Mar 17, 2020 at 0:58
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    $\begingroup$ If the Earth were 380,000 km away at this moment, then we need to hold this photo at a distance of 4.8 times it's displayed width to see the Earth with about the right angular width, which would be about 1.9 degrees. I don't see any continents, but then again I don't have anything like astronaut-grade vision (nor anything else astronaut-like for that matter) $\endgroup$
    – uhoh
    Commented Mar 17, 2020 at 1:11
  • $\begingroup$ That Harrison Schmitt photo is about what I expected. $\endgroup$
    – Bob516
    Commented Mar 17, 2020 at 1:13
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    $\begingroup$ You can see "continental-scale" features of the moon's surface from the Earth with the naked eye; Earth seen from the moon is ~4 times that large. This and the Schmitt photo are both not as ideally contrasted as the human visual system should be able to perceive. $\endgroup$
    – Russell Borogove
    Commented Mar 17, 2020 at 1:19
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There is a nice Wikipedia image of Earth (ø = 12,756 km) and Moon (ø = 3,476 km) at the same scale.

When you look up to the full Moon at night with a clear sky you are able to see many details. The astronauts looked up to the much bigger Earth at the same distance. So they were able to see much more details of Earth than we see of the Moon.

The famous Earthrise photo was taken with a 250 mm telephoto lens, not with the 80 mm standard lens. It does not show a view similar to the naked eye view.

enter image description here

Image source: https://www.lpi.usra.edu/resources/apollo/frame/?AS08-14-2384

enter image description here

Taken with a 80 mm standard lens it would look like this.

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