# Why can't Hubble see the Apollo landing sites? **URL:** \ **Category:** Factual Questions\ **Created:** [August 5, 2005, 12:43am UTC](https://boards.straightdope.com/t/why-cant-hubble-see-the-apollo-landing-sites/315648 "2005-08-05T00:43:33Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Sequent](https://avatars.discourse-cdn.com/v4/letter/s/dbc845/32.png) [@Sequent](https://boards.straightdope.com/u/Sequent)\ **Post date:** [August 5, 2005, 12:43am UTC](https://boards.straightdope.com/t/why-cant-hubble-see-the-apollo-landing-sites/315648/1 "2005-08-05T00:43:33Z")
Googling the moon made me wonder: [http://moon.google.com/](http://moon.google.com/) I remember hearing some speculation a while back that the VLT at Mt. Paranal would, when completed and fully functional, be strong enough to view the moon in enough detail to resolve some details from the Apollo landing sites. What doesn’t make sense is how, with Hubble, we can see soooo far away that we can actually image [galaxies that are 13 billion years old](http://antwrp.gsfc.nasa.gov/apod/ap040309.html) …and yet we can’t see the moon in enough detail to disprove conspiracy theorists? You’d think we’d be able to see Armstrong’s footprints with that kind of power, but obviously, there’s something I’m missing. Something basic about focal length? Or is the Hubble simply not capable of viewing objects so close to it? Or is seeing that kind of detail on the moon just a lot more difficult that it would seem? And one misc. question that been bugging me: how do you pronounce “Kupier” (as in the Kupier Belt)? I’ve heard it pronounced such that it rhymes with “hyper.” ---
**Author:** ![Sequent](https://avatars.discourse-cdn.com/v4/letter/s/dbc845/32.png) [@Sequent](https://boards.straightdope.com/u/Sequent)\ **Post date:** [August 5, 2005, 12:47am UTC](https://boards.straightdope.com/t/why-cant-hubble-see-the-apollo-landing-sites/315648/2 "2005-08-05T00:47:54Z")
…looking at the moon on Google: why did we keep going to the same place on the moon? I mean, six shots, we couldn’t have picked a few different spots to try? They all look pretty close together, relatively speaking. Like going to Earth six times and landing in the midwest all of them. Logistical issues? ---
**Author:** ![Merijeek](https://avatars.discourse-cdn.com/v4/letter/m/f05b48/32.png) [@Merijeek](https://boards.straightdope.com/u/Merijeek)\ **Post date:** [August 5, 2005, 12:48am UTC](https://boards.straightdope.com/t/why-cant-hubble-see-the-apollo-landing-sites/315648/3 "2005-08-05T00:48:23Z")
I’m going to take a wild guess that the Hubble is, essentially, farsighted? -Joe, nearsighted in one eye ---
**Author:** ![Sequent](https://avatars.discourse-cdn.com/v4/letter/s/dbc845/32.png) [@Sequent](https://boards.straightdope.com/u/Sequent)\ **Post date:** [August 5, 2005, 12:51am UTC](https://boards.straightdope.com/t/why-cant-hubble-see-the-apollo-landing-sites/315648/4 "2005-08-05T00:51:27Z")
That was my guess. I’ve also found articles saying that it’s because the moon is too bright. But the Hubble [can do it](http://hubblesite.org/newscenter/newsdesk/archive/releases/1999/14/)…just only so well, apparently. ---
**Author:** ![Bryan\_Ekers](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bryan_ekers/32/183_2.png) [@Bryan\_Ekers](https://boards.straightdope.com/u/Bryan_Ekers)\ **Post date:** [August 5, 2005, 12:53am UTC](https://boards.straightdope.com/t/why-cant-hubble-see-the-apollo-landing-sites/315648/5 "2005-08-05T00:53:38Z")
The distant starts have very little relative motion, whereas the moon is zipping along at about a kilometer a second. This makes it hard to focus and track and object as small as an Apollo landing site. Besides, even if you _had_ the pictures, the conspiracy nuts would claim they were faked. There’s no victory to be had. ---
**Author:** ![Cerowyn](https://avatars.discourse-cdn.com/v4/letter/c/82dd89/32.png) [@Cerowyn](https://boards.straightdope.com/u/Cerowyn)\ **Post date:** [August 5, 2005, 1:04am UTC](https://boards.straightdope.com/t/why-cant-hubble-see-the-apollo-landing-sites/315648/6 "2005-08-05T01:04:51Z")
The reason we can see remote stars and not the Apollo landing sites has to do with scale. Stars are big. Very, very big. The landing sites, not so much. To use the [NASA’s own example](http://hubblesite.org/reference_desk/faq/answer.php.id=77&cat=topten), a 4 metre object on the moon would be about 0.002 arc seconds in size from the Hubble. The maximum resolution for any instrument on the Hubble is about 0.03 arcsec, an order of magnitude too poor. ---
**Author:** ![Bytegeist](https://avatars.discourse-cdn.com/v4/letter/b/9dc877/32.png) [@Bytegeist](https://boards.straightdope.com/u/Bytegeist)\ **Post date:** [August 5, 2005, 1:05am UTC](https://boards.straightdope.com/t/why-cant-hubble-see-the-apollo-landing-sites/315648/7 "2005-08-05T01:05:37Z")
> [@Sequent](#): > > What doesn’t make sense is how, with Hubble, we can see soooo far away that we can actually image [galaxies that are 13 billion years old](http://antwrp.gsfc.nasa.gov/apod/ap040309.html) …and yet we can’t see the moon in enough detail to disprove conspiracy theorists? Hubble’s angular resolution is about 0.05 arcseconds, or about 1 / 70,000th of a degree. Armstrong’s footprint (call it 0.2 meters long) at the distance of the Moon (384,000 km) would subtend an angle of about 1 / 33,000,000th of a degree. So it’s much too small _and_ far away, together, for Hubble to resolve. Galaxies are pretty damn far away to be sure, but they’re also much **much** larger. > [@](#): > > … how do you pronounce “Kupier” (as in the Kupier Belt)? I’ve heard it pronounced such that it rhymes with “hyper.” I’ve always heard it pronounced like a French name: “Ku-pi-yay”. That’s from astronomers I’ve known. ---
**Author:** ![Stranger\_On\_A\_Train](https://avatars.discourse-cdn.com/v4/letter/s/13edae/32.png) [@Stranger\_On\_A\_Train](https://boards.straightdope.com/u/Stranger_On_A_Train)\ **Post date:** [August 5, 2005, 1:08am UTC](https://boards.straightdope.com/t/why-cant-hubble-see-the-apollo-landing-sites/315648/8 "2005-08-05T01:08:39Z")
> [@Sequent](#): > > …looking at the moon on Google: why did we keep going to the same place on the moon? I mean, six shots, we couldn’t have picked a few different spots to try? They all look pretty close together, relatively speaking. Like going to Earth six times and landing in the midwest all of them. Logistical issues? We didn’t pick sites that were all that close together. See [this map](http://www.nasm.si.edu/collections/imagery/apollo/FIGURES/LandingSitesMaps.jpg) for a better view. We did pick sites on the near side for obvious communications reasons, and relatively near the equator for reasons of orbital ballistics (it takes less fuel to land and take off at near the equator than it does nearer the poles), but the sites are fairly far apart. Hubble can’t see the landing sites because its visual resolution isn’t fine enough. Hubble was designed as a deep field telescope (narrow angle at long range) but the real reason it can’t see footprints on the Moon is that no optical instrument is capable of making that degree of image refinement; Hubble has a resolution of about .03 seconds of arc. A 4 meter object would have about .002 seconds of arc according to [this faq](http://hubblesite.org/reference_desk/faq/answer.php.id=77&cat=topten). A footprint would have an image of apprxomately two orders of magnitude less than that. Anybody who claims to be able to see footprints on the Moon from an Earth-based telescope is selling pipe dreams. Kuiper (not Kupier) is pronounced “k-eye-per”, rhyming, as you indicate, with hyper. Stranger ---
**Author:** ![Sequent](https://avatars.discourse-cdn.com/v4/letter/s/dbc845/32.png) [@Sequent](https://boards.straightdope.com/u/Sequent)\ **Post date:** [August 5, 2005, 1:12am UTC](https://boards.straightdope.com/t/why-cant-hubble-see-the-apollo-landing-sites/315648/9 "2005-08-05T01:12:23Z")
Thanks, y’all. Apparently this is one of NASA’s most FAQ :smack: So I guess what I heard about the VLT was just hot air…at least when it comes to seeing the footprints. Maybe we’ll at least be able to see the sound stage where they faked the landings…that should be big enough. :rolleyes: ---
**Author:** ![Waenara](https://avatars.discourse-cdn.com/v4/letter/w/50afbb/32.png) [@Waenara](https://boards.straightdope.com/u/Waenara)\ **Post date:** [August 5, 2005, 1:14am UTC](https://boards.straightdope.com/t/why-cant-hubble-see-the-apollo-landing-sites/315648/10 "2005-08-05T01:14:43Z")
> [@Stranger On A Train](#): > > > [@](#): > > > > Originally Posted by **Sequent** > > …looking at the moon on Google: why did we keep going to the same place on the moon? I mean, six shots, we couldn’t have picked a few different spots to try? They all look pretty close together, relatively speaking. Like going to Earth six times and landing in the midwest all of them. Logistical issues? > > We didn’t pick sites that were all that close together. See [this map](http://www.nasm.si.edu/collections/imagery/apollo/FIGURES/LandingSitesMaps.jpg) for a better view. We did pick sites on the near side for obvious communications reasons, and relatively near the equator for reasons of orbital ballistics (it takes less fuel to land and take off at near the equator than it does nearer the poles), but the sites are fairly far apart. Also, remember that all of the landings took place on the nearside of the moon. Since the moon is tidally locked (I think that’s the term), one side is constantly facing Earth. If the astronauts wanted to be able to communicate with Mission Control during the landing, they wouldn’t be able to land on the farside. So that right there cuts the number of possible landing sites in half. Also, IIRC the farside of the moon is on average more mountainous/rougher terrain than the nearside. ---
**Author:** ![Washoe](https://avatars.discourse-cdn.com/v4/letter/w/ecae2f/32.png) [@Washoe](https://boards.straightdope.com/u/Washoe)\ **Post date:** [August 5, 2005, 1:21am UTC](https://boards.straightdope.com/t/why-cant-hubble-see-the-apollo-landing-sites/315648/11 "2005-08-05T01:21:16Z")
> [@Sequent](#): > > Maybe we’ll at least be able to see the sound stage where they faked the landings…that should be big enough. :rolleyes: Don’t be silly—you know damn well that the entire setup has been dismantled and is being stored in a hanger at Area 51. ---
**Author:** ![Mr.Blue\_Sky](https://avatars.discourse-cdn.com/v4/letter/m/d26b3c/32.png) [@Mr.Blue\_Sky](https://boards.straightdope.com/u/Mr.Blue_Sky)\ **Post date:** [August 5, 2005, 1:25am UTC](https://boards.straightdope.com/t/why-cant-hubble-see-the-apollo-landing-sites/315648/12 "2005-08-05T01:25:10Z")
> [@Washoe](#): > > Don’t be silly—you know damn well that the entire setup has been dismantled and is being stored in a hanger at Area 51. I’d be on the lookout for black helicopters if I were you. 😃 ---
**Author:** ![drewbert](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/drewbert/32/15890_2.png) [@drewbert](https://boards.straightdope.com/u/drewbert)\ **Post date:** [August 5, 2005, 1:46am UTC](https://boards.straightdope.com/t/why-cant-hubble-see-the-apollo-landing-sites/315648/13 "2005-08-05T01:46:07Z")
> [@Sequent](#): > > So I guess what I heard about the VLT was just hot air… Funny you should mention hot air. Even if a telescope _could_ be built big enough to get that sort of detail on the Moon (an engineering problem but AFAIK theoretically possible) the turbulence in the Earth’s atmosphere would smear out any details that small anyway. ---
**Author:** ![Merijeek](https://avatars.discourse-cdn.com/v4/letter/m/f05b48/32.png) [@Merijeek](https://boards.straightdope.com/u/Merijeek)\ **Post date:** [August 5, 2005, 1:46am UTC](https://boards.straightdope.com/t/why-cant-hubble-see-the-apollo-landing-sites/315648/14 "2005-08-05T01:46:28Z")
> [@Sequent](#): > > Thanks, y’all. Apparently this is one of NASA’s most FAQ :smack: > > So I guess what I heard about the VLT was just hot air…at least when it comes to seeing the footprints. Maybe we’ll at least be able to see the sound stage where they faked the landings…that should be big enough. :rolleyes: A soundstage has a roof. Duh! -Joe, 🙂 ---
**Author:** ![Bryan\_Ekers](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bryan_ekers/32/183_2.png) [@Bryan\_Ekers](https://boards.straightdope.com/u/Bryan_Ekers)\ **Post date:** [August 5, 2005, 1:47am UTC](https://boards.straightdope.com/t/why-cant-hubble-see-the-apollo-landing-sites/315648/15 "2005-08-05T01:47:40Z")
Truman [examining 1947 Roswell spaceship debris]: Whistlin’ dixy! I want this sent to Area 51 for study! General: But Sir! That’s where we’re building our fake moon landing set. Truman: Then we’ll have to _really_ land on the moon. Invent NASA and tell them to get off their fannies! ---
**Author:** ![Sequent](https://avatars.discourse-cdn.com/v4/letter/s/dbc845/32.png) [@Sequent](https://boards.straightdope.com/u/Sequent)\ **Post date:** [August 5, 2005, 1:52am UTC](https://boards.straightdope.com/t/why-cant-hubble-see-the-apollo-landing-sites/315648/16 "2005-08-05T01:52:59Z")
> [@](#): > > Dr West said that the challenge pushed the optical abilities of one VLT mirror to its limits: if this attempt failed, the team planned to use the power of all four mirrors. “They would most probably be sufficiently sharp to show something at the sites,” he said. [http://portal.telegraph.co.uk/news/main.jhtml?xml=/news/2002/11/24/nmoon24.xml](http://portal.telegraph.co.uk/news/main.jhtml?xml=/news/2002/11/24/nmoon24.xml) ---
**Author:** ![drewbert](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/drewbert/32/15890_2.png) [@drewbert](https://boards.straightdope.com/u/drewbert)\ **Post date:** [August 5, 2005, 1:58am UTC](https://boards.straightdope.com/t/why-cant-hubble-see-the-apollo-landing-sites/315648/17 "2005-08-05T01:58:16Z")
Ah. Adaptive optics. Duh. I retract my previous post. :smack: Impressive feat, if they can do it. ---
**Author:** ![douglips](https://avatars.discourse-cdn.com/v4/letter/d/e68b1a/32.png) [@douglips](https://boards.straightdope.com/u/douglips)\ **Post date:** [August 5, 2005, 2:11am UTC](https://boards.straightdope.com/t/why-cant-hubble-see-the-apollo-landing-sites/315648/18 "2005-08-05T02:11:52Z")
The mechanism that limits an optical telescope is the [Rayleigh Criterion](http://hyperphysics.phy-astr.gsu.edu/hbase/phyopt/raylei.html). The basic idea is that at a certain resolution, the diffraction of light entering the telescope will overcome details in the image. To be able to resolve the lunar landers, which would subtend an angle of approximately .003 arcsec, would require an optical telescope of at least 210 meters in diameter. The largest optical telescope currently is 10 meters. The biggest scopes under construction are about 22 meters, using the voodoo of optical interferometry. ([Big Telescopes link](http://astro.nineplanets.org/bigeyes.html#keckint)) On top of that, it would have to have adaptive optics and/or be outside the earth’s atmosphere. We think that the moon is pretty close by astronomic measures, but it’s still a freaking long ways away. Oh, and Hubble isn’t really appreciably closer to the Moon than we are - it’s 150 miles closer, out of 250,000. Peanuts. ---
**Author:** ![Sequent](https://avatars.discourse-cdn.com/v4/letter/s/dbc845/32.png) [@Sequent](https://boards.straightdope.com/u/Sequent)\ **Post date:** [August 5, 2005, 2:16am UTC](https://boards.straightdope.com/t/why-cant-hubble-see-the-apollo-landing-sites/315648/19 "2005-08-05T02:16:53Z")
> [@](#): > > The nominal image sharpness is 0.07 arcsec, or about 130 metres on the lunar surface (in the N-S direction). [http://www.eso.org/outreach/press-rel/pr-2002/phot-19-02.html](http://www.eso.org/outreach/press-rel/pr-2002/phot-19-02.html) ---
**Author:** ![JimMacMillan](https://avatars.discourse-cdn.com/v4/letter/j/7bcc69/32.png) [@JimMacMillan](https://boards.straightdope.com/u/JimMacMillan)\ **Post date:** [August 5, 2005, 3:00am UTC](https://boards.straightdope.com/t/why-cant-hubble-see-the-apollo-landing-sites/315648/20 "2005-08-05T03:00:21Z")
> [@Waenara](#): > > Also, remember that all of the landings took place on the nearside of the moon. Since the moon is tidally locked (I think that’s the term), one side is constantly facing Earth. If I have misunderstood what you are trying to say please forgive me. 😉 The moon does a complete rotation every 24 hours. Since it matches earths rotation a person in the USA would see the same face where as someone in say China sees a different face. Jim [Next page](https://boards.straightdope.com/t/why-cant-hubble-see-the-apollo-landing-sites/315648.md?page=2)