There are interferometers that fuse the images produced by multiple telescopes and achieve a resolution of 0.001 arcseconds. With changes, couldn't these observe the Moon landers? Is the reason why nobody is seeing the Moon landers related to effort and not actual technical limitations (besides atmosphere interference, brightness, time use, and other general issues)?

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    $\begingroup$ Another reason is that nobody with an ounce of intelligence could be bothered with doing so? The detritus of the Moon landings have already been imaged from orbit. What do you think the purpose of obtaining some more grainy images would be? $\endgroup$
    – ProfRob
    Commented Sep 4, 2019 at 7:09
  • $\begingroup$ en.m.wikipedia.org/wiki/… $\endgroup$
    – ProfRob
    Commented Sep 4, 2019 at 7:15
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    $\begingroup$ What would be the point of such an exercise? The promulgators of the "The Moon landing was a hoax" meme would reject such imagery, just like they have rejected Every. Other. Piece of evidence that humans did land on the Moon. There is no doubt that humans did land on the Moon, six separate times. Time on those expensive telescopes is allocated judiciously, with the primary metric being the expected scientific payoff. Pointing such telescopes toward the Moon would be an absolute waste of those very precious resources. $\endgroup$ Commented Sep 5, 2019 at 13:21

1 Answer 1


Is seeing the apollo moon Landers via earth telescope that hard?

Yes, it still is.

If the resolution of an interferometric telescope is really 0.001 arcseconds, that translates to 4.85E-09 radians. At a perigee of 362,600 km that's 1.8 meters.

The top part lower half of the Lunar Modules (that remain on the surface after the astronauts leave) is about 4.2 meters wide which is a little more than double the resolution, so if there is some good contrast then it might appear in a reconstructed interferometric image.

However, those optical interferometers are not designed for imaging of extended objects. They only have a few telescopes and so are mostly limited to resolving more than one point-like object from each other, such as a double star or a star and an exoplanet.

With so few telescopes in an optical interferometer, a complex image like lunar terrain would be difficult or impossible to reconstruct without a model. For example, the images of the accretion disk of a black hole by the event horizon telescope required some input modeling to interpret the interferometric data.

Near sunrise or sunset however, the shadow of a lunar lander will be much larger. The lander is about 7 3.5 meters tall, so the shadow could be 4 or more meters wide by several tens of a dozeon meters long. Since the Moon's orientation, as well as that of the lander and the local terrain is extremely well documented, then at each moment you could estimate what the shadow would look like in size, shape, and orientation. With that model, an interferometric image based on a few telescopes could be used to confirm the shadow.

However, using a model like that won't appease conspiracy theorists.

enter image description here Source

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    $\begingroup$ Is it true that the longer the lander isn't observed, the less likely it is to be real? $\endgroup$
    – user29247
    Commented Sep 4, 2019 at 3:34
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    $\begingroup$ @user29247 Unless your cat is doing the non-observing $\endgroup$ Commented Sep 4, 2019 at 18:21
  • $\begingroup$ But if telescopes continue to improve/get larger will it happen? $\endgroup$
    – user29247
    Commented Sep 4, 2019 at 18:25
  • $\begingroup$ Just as a nit to this otherwise excellent answer, the part of the landers that remain on the moon are only the decent stages, and those are only (approximately) half the height of the overall lander, because the cabin/ascent modules are no longer present on the moon. To be more correct, however, 5 of the 6 ascent modules are on the moon, but not intact since they (except for Apollo 13) left the ascent modules in orbit around the moon to eventually crash back onto the lunar surface. $\endgroup$
    – Milwrdfan
    Commented Jul 14, 2023 at 20:10
  • $\begingroup$ @Milwrdfan oh my goodness - those are several meter tall nits! Okay I've made an adjustment, thanks! $\endgroup$
    – uhoh
    Commented Jul 15, 2023 at 6:14

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