127

This image is circulating on Facebook.


All American flags placed on the moon are now white due to radiation from the sun

Great, now it looks like the French went there...

Did the US flags on the moon turn white?

Community
  • 1
Greg Mike
  • 1,051
  • 2
  • 7
  • 6
  • 79
    Previous.comments established some people didn't get the joke, some people didn't like the joke, and some people still believe the meanings of words can be precisely determined by their etymology. None of this is relevant to the question and has been deleted. – Oddthinking Apr 25 '18 at 21:12

2 Answers2

191

They are either bleached white or completely disintegrated.

This NASA website repeats some expert speculation on the topic.

For forty-odd years, the flags have been exposed to the full fury of the Moon’s environment – alternating 14 days of searing sunlight and 100° C heat with 14 days of numbing-cold -150° C darkness. But even more damaging is the intense ultraviolet (UV) radiation from the pure unfiltered sunlight on the cloth (modal) from which the Apollo flags were made. Even on Earth, the colors of a cloth flag flown in bright sunlight for many years will eventually fade and need to be replaced. So it is likely that these symbols of American achievement have been rendered blank, bleached white by the UV radiation of unfiltered sunlight on the lunar surface. Some of them may even have begun to physically disintegrate under the intense flux.

Of the three experts quoted, this one is actually the most optimistic. All three agree that the flags would be bleached white. Two of them believe that the flags then turned to ash. The meme shows a flag that is bleached white, but otherwise intact; this is almost certainly not the case. No one has actually been back to look at the flags, and our best orbital pictures don't show the flags in any detail, so we can't know for sure.

The Lunar Reconnaissance Orbiter has been orbiting the moon since 2009 taking "high resolution" images. If you look closely at some of these images, it is possible to see the shadows cast by some of the flags. This means that those flags are still standing, but doesn't give a lot of information about their condition.

ivan_pozdeev
  • 103
  • 3
BobTheAverage
  • 11,961
  • 6
  • 43
  • 54
  • 13
    So is there a material they could have been made from (ignoring weight, expense, etc.) that *would* have survived and kept its full color? – Alexander Apr 25 '18 at 19:47
  • 4
    @Alexander yes; work *with* the environment rather than against it. For example, many minor planets are red because of the effects of the space environment. So make the red pigment out of that. – JDługosz Apr 25 '18 at 20:48
  • 115
    @Alexander Undoubtedly there is, but instead of spending money on that, "they literally sent out a secretary to the nearby Sears and bought an off-the-shelf flag and modified it." The flags did their jobs admirably. The only purpose of a more resilient flag would be to prevent snarky Facebook memes. – BobTheAverage Apr 25 '18 at 20:52
  • 4
    I would assume a glass fibre cloth, with anorganic pigments in the glass fibres, would stand some chance.... or metal foil that had tempering colors applied to it by heating.... – rackandboneman Apr 25 '18 at 21:56
  • 5
    @Alexander If cost and weight truly aren't factors, the flag could me made out of many kinds of gemstones. [Quartz](https://en.wikipedia.org/wiki/Quartz) for example, comes in a variety of colors and is an incredibly durable crystal. [Sapphire](https://en.wikipedia.org/wiki/Sapphire) is another good candidate. Both are extremely sturdy and mostly transparent to the wavelengths of UV that damage cloth/dye. Plus you'd have one seriously baller "flag" (you never said it had to be cloth!) – thanby Apr 26 '18 at 11:21
  • 1
    But the image as posted in the question is without any doubt photoshopped, why not mention this in the answer? – Shadow The GPT Wizard Apr 26 '18 at 12:20
  • 39
    @ShadowWizard: Because no-one believes it wasn't photoshopped. The photoshop was obvious and part of the joke. It still has astronauts in the image, whereas the claim is is about now. – Oddthinking Apr 26 '18 at 14:12
  • 1
    @Alexander In theory, "structural blue" doesn't fade (I think)... – user3067860 Apr 26 '18 at 15:33
  • 16
    @Oddthinking: You, you may be overestimating the reasoning powers of meme-consumers... :-) – T.J. Crowder Apr 26 '18 at 16:25
  • 2
    @Oddthinking: I bet there are billions of people who don't know that humans haven't landed on the Moon since 1972. (But I agree that it's not a big deal. This answer makes clear that we don't know exactly what the flags look like now, which we obviously *would* if the picture were real.) – ruakh Apr 26 '18 at 17:14
  • 8
    "The Lunar Reconnaissance Orbiter has been orbiting the moon since 2009 taking "high resolution" images. If you look closely at some of these images, it is possible to see the shadows cast by some of the flags. " - Link(s), please. – aroth Apr 27 '18 at 01:22
  • 1
    @user3067860 You mean color by iridescence, as in butterfly wings? True: They are not caused by pigments but by nano structures refracting light and causing interference which can create waves at specific wavelengths. The color depends, iiuc, on the grid scale so that all colors of the spectrum are possible, I assume (there is some green at the bottom of http://www.webexhibits.org/causesofcolor/15A.html). The question is whether nano structures (of which material?) deteriorate over decades in harsh UV (and gamma etc. from cosmic rays), which I assume is a real possibility. – Peter - Reinstate Monica Apr 27 '18 at 09:21
  • @Oddthinking: inb4 "are those astronauts bleached white and/or turned to ash by now?" – Lightness Races in Orbit Apr 29 '18 at 11:48
  • 1
    @aroth http://www.bbc.co.uk/news/science-environment-19050795 - LRO pics of Apollo 16 landing site. – WhatEvil Apr 30 '18 at 15:20
  • LRO pics of Apollo landing sites, original source: https://www.nasa.gov/mission_pages/LRO/multimedia/lroimages/apollosites.html and https://www.nasa.gov/mission_pages/LRO/news/apollo-sites.html and the complete archive: https://www.nasa.gov/mission_pages/LRO/multimedia/lroimages/LROMoonImages_archive_1.html – Hobbes May 01 '18 at 14:04
  • @Alexander Gabriel Lippmann, winner of the Nobel Prize in 1908 devised the first color photographs without pigment, by using very small silver crystal sizes and wavelength interference. One might have a lot of fun imagining if such a technique could be leveraged to create a more UV resistant non-pigment coloring agent. – Edwin Buck May 02 '18 at 01:43
  • @Alexander-ReinstateMonica you do realize that sending a flag is a big criminal operation and an act against humanity? And that those responsible for setting it up should be executed at sight? Space and the moon is decided to be neutral country, for all humanity equal. As such political symbols have no point being there, and the US personel and their descendants should be destroyed! – paul23 Dec 03 '20 at 00:49
  • @paul23 chill on the genocidal sentiments, my dude. – Alexander Dec 03 '20 at 02:25
8

Nobody knows what colors the flags are. Experts hypothesise that the color has faded by now due to prolonged exposure to intense UV radiation, but we have no direct or indirect evidence for that. We do have evidence that the flags of Apollo 12, Apollo 16, and Apollo 17 are still standing as inferred from shadows seen on the Lunar Reconnaissance Orbiter. https://www.hq.nasa.gov/alsj/ApolloFlags-Condition.html

user2705196
  • 404
  • 2
  • 7
  • 12
    It would be good to quote the relevant sections that support your claims, to protect against link rot. No *indicrect* evidence is a rather strong statement. We have evidence about the strong UV light on the moon, and we have evidence of the effect UV light has on bleaching dyes. Both of those are indirect evidence to support the hypothesis that the flags have faded. – Oddthinking Apr 27 '18 at 02:32
  • 2
    That's the same link as the answer posted a day before. This answer doesn't seem to add anything that wasn't already said, except the mission numbers. Could have been a comment or edit suggestion. – Peter Cordes Apr 27 '18 at 06:53
  • 3
    I like this answer better, there is no clear answer as the other tries to make. Photooxidation does not occur without oxygen, other forms of bleaching may, same as in a LEO – daniel Apr 27 '18 at 13:38
  • 1
    @daniel nice point. If it is an oxidative process (UV + O2) than we really don't know without an experiment trying to fade flags in a vacuum or oxygen free environment. Question is silly, answer is hubris and there simply isn't any way to really know without running an experiment in a hot and cold vacuum chamber bathed in UV and gathering evidence. – geoO May 14 '18 at 00:11