During the Apollo missions the astronauts of the Apollo 15,16,and 17 performed cislunar space EVAs to check on experiments located in an external bay but said they could see no stars: Transcript from A16:

219 00 33 Mattingly (EVA): It is that, all right. I don't even see any stars.

219 33 44 Duke (onboard): Okay. Can you see the sunsight?

219 33 46 Young (onboard): On this - on this event timer, Charlie, I got 04:16. Is that right?

219 33 50 Duke (onboard): That thing ain't working. No. Can you see the sunsight, Ken?

219 33 57 Mattingly (EVA): No, sir.

219 36 48 Mattingly (EVA): You get a good look at the Earth, Charlie?

219 36 49 Duke (onboard): Oh, yeah. And I spun around and looked at the Moon, too. The thing that impresses me, though, is how black it is, Ken. Yeah, is it black!

219 37 05 Mattingly (EVA): I'm really surprised I don't see any stars.

219 37 07 Young (onboard): Charlie's only said 25 times it's black out there.

219 37 11 Duke (onboard): What?

219 37 12 Young (onboard): You've only said that 25 times. (Laughter)

219 37 14 Duke (onboard): (Garble) see (garble) (laughter).

219 37 15 Young (onboard): It really must be black out there! (Laughter)

219 37 17 Duke (onboard): It's really black! (Laughter)

What possible reason is there for them not being able to see the stars?


1 Answer 1


"The sky is full of stars!"

While not on these three spacewalks, astronauts in cis-lunar have indeed seen stars, and this is documented in transcripts!

From Seeing stars from cislunar space?

Did any of the Apollo astronauts describe seeing the stars as they travelled between the Earth and the Moon?


Yes. They did see stars. Here is an excerpt from the Apollo 11 Transcript.

02 23 59 20 CDR: Houston, it's been a real change for us. Now we are able to see stars again and recognize constellations for the first time on the trip. It's - the sky is full of stars. Just like the nightside of Earth. But all the way here, we have only been able to see stars occasionally and perhaps through the monocular, but not recognize any star patterns.

02 23 59 52 CC: I guess it has turned into night up there really, hasn't it ?

This happened when the Sun was eclipsed by the Moon. So it was essentially night for them. There is no atmosphere, and there is no bright light from the Sun (there was Earth-shine though) which meant seeing stars would've been incredibly easy.

However, on the three space walks you've chosen there was no eclipse, no "essentially night" conditions. Instead they were directly sunlit which is even brighter in space than on the ground, and were likely using protective visors.


The three EVAs in question were all in cis-lunar space during the return trips from the Moon and not in lunar orbit, so there was no possibility of eclipse, and there would not have been any, they would have needed plenty of light to perform the film cassette retrievals (the primary purposes of the EVAs).

The astronauts would have been looking at white surfaces in daylight right in front of them, so their pupils would have been constricted as they would be in an absurdly brightly lit room that matched 130% of daylight at noon at the Equator (visible light above the Earth's atmosphere is 1/3 brighter than it is on Earth's surface)

Now imagine being accustomed to that level of illumination and having a moment to look out a skylight or window at the night sky. Will you be seeing a lot of stars?

No. You won't.

Had an astronaut been able to get several minutes of free time to choose a position to put themselves and look in a direction such that neither the Sun nor any reflecting surface was in their field of view, then opened their helmet's visor, they could have partially adjusted their vision to night conditions, and then would have seen stars.

But they couldn't, so they didn't.

  • 1
    $\begingroup$ "Astronaut Dave Scott did see few bright stars on the lunar surface but only when standing in the shadow of the LM for some time with his visor up." Do you have a reference for him saying that? $\endgroup$
    – Solon
    Commented Oct 17, 2021 at 23:42
  • $\begingroup$ @Solon I don't see that quote anywhere here except in your comment. Did you put it under the wrong post? Or was another comment since deleted? It sounds interesting! $\endgroup$
    – uhoh
    Commented Oct 18, 2021 at 0:46
  • $\begingroup$ Well, I cut and pasted that statement from somewhere on this site, maybe I'm getting senile in my old age? $\endgroup$
    – Solon
    Commented Oct 18, 2021 at 18:55
  • 1
    $\begingroup$ @Solon one is facing a matte white surface illuminated by sunlight 30% brighter than noon on Earth's surface at the equator. The number doesn't matter, it's really bright! $\endgroup$
    – uhoh
    Commented Oct 18, 2021 at 21:31
  • 1
    $\begingroup$ @Solon I have a table inclined by a few degrees from local horizontal. Do I need to measure the coefficient of static friction of my coffee cup and he exact inclination of the table's surface before I dare set my coffee cup down on the inclined table, or do I conclude "obviously flat enough" and go ahead and set it down? $\endgroup$
    – uhoh
    Commented Oct 19, 2021 at 20:58

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