Rolling Rock’s bucket o’ Moon graffiti

By Phil Plait | March 5, 2008 3:30 pm

Via Digg I heard that the makers of Rolling Rock beer want to, um, Moonvertise.

That is, use a laser to paint an ad on the Moon.


So I checked out the Rolling Rock moonvertising website. Then I waited several minutes for their incredibly bad and slow-loading Flash page to come up on my browser.

Strike One.

Then, obnoxious music and sound effects blared out my speaker, and it wasn’t obvious at first how to turn them down or off.

Strike Two.

Then, their Flash animation started eating up all my CPU.

Strike Three.


OK, I still hung out to figure out what the heck this was about. The idea, according to the site, is that they will use a big laser to shine their logo on the full Moon. Let’s be clear up front: this is a joke. It took me about three seconds (after the ten minute loading to finish) to figure that out.

<Pedant mode ON>

Realistically, it’s not possible to do what they want to do. The Moon is a quarter million miles away, and lasers spread. Even tightly focused beams will spread out hugely by that distance. That means the power gets spread out, so the laser is pretty dim by the time it gets to the Moon.

Then, the light has to be reflected back to the Earth. The Moon is really not terribly reflective; its average albedo is about 12%, which means it reflects only 12% of the light that hits it. So you lose 7/8 of the light you send there anyway.

Of course, a laser powerful enough to overcome all this would probably have military applications, since it would have enough power to slice an incoming missile in half. Calling Chris Knight and Mitch Taylor! I imagine the FAA might be a little concerned about planes in the area, too. Any birds that happen to fly too close might be fried… hmmmm, does crow go with beer?

And, duh of duhs, they say they are doing this during the full Moon, when the surface of the Moon is lit up by the Sun! The best time to do this would be around first quarter, when the Moon is half dark, and up during the early evening. That way the surface is dark and provides contrast, and more people will be around to see it.

<Pedant mode OFF>

So this is a clever idea as far as satirical advertising goes, and not meant to be taken seriously… which hasn’t stopped people, of course.

But, if it gets people to go outside and look at the full Moon, well, that’s still pretty cool. We’ll see.

Or not.

CATEGORIZED UNDER: Astronomy, Debunking, Humor, Skepticism

Comments (94)

Links to this Post

  1. Rolling Rock’s bucket o’ Moon graffiti-music | March 5, 2008
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  7. Moonvertising | March 18, 2008
  1. Michelle

    I hope no one really digs that. Seriously. Oh and uh, NICE MARKETING! Looks like they got what they wanted.

  2. silence

    Is this any different from the PaintTheMoon guy who was around a few years ago?

  3. At least they’re not trying to use the laser to write “Chairface” or anything…

  4. BaldApe

    If their website’s so crappy, one has to wonder how they would manage it, even if it were possible.

  5. Martinus

    Perhaps someone has read Arthur C. Clarke’s 1956 story “Watch This Space”.

  6. PrimeMover

    Didn’t the astronauts who went to the moon leave behind mirrors that us earthlings use to bounce a laser off them & precisely calculate the distance to the moon??? Phil, how does that work if you say the laser spreads out at such a great distance??

  7. Aerimus

    Psh! Everyone knows that you’re suppose to use the laser to carve your name into the moon. Whether you should do so before or after the planet eating alien takes a chunk out of it, I don’t recall…

  8. MandyDax

    I remember when the thought of space advertising was being bandied about. The thought that Nike might pay to have a rocket deploy a reflective mylar swoosh that folds out to be a few miles across chilled me to the core. I should hope that anyone who actually did something like that would be boycotted right out of business, and the Navy would shoot down their sky graffiti.

  9. JohnW

    Calling Chris Knight and Mitch Taylor!

    Heh. No love for Lazlo?

  10. Miniver Cheevy

    We already know you’re a geek — going for the Real Genius reference isn’t necessary…

  11. “Realistically, it’s not possible to do what they want to do. The Moon is a quarter million miles away, and lasers spread. Even tightly focused beams will spread out hugely by that distance. That means the power gets spread out, so the laser is pretty dim by the time it gets to the Moon. ”

    Wait a second, is this relevant to the post the other day about gamma ray bursts, or would they not spread out in the same way (over their hypothetical 8000 l.y. journey from WR104 to Earth)?

  12. Ian


    They use high-powered lasers and extremely sensitive detectors. The other day I was told about The APOLLO lunar-ranging laser program, where they fire off short pulses of laser light at about 1 gigawatt, which in this case turns out to be about 320 quadrillion photons per pulse. They use a 3.5m telescope to receive the returning photons, of which they detect only about 3 per pulse.

  13. Buzz Parsec

    PrimeMover –

    They beam the laser out through a large (5 meter class) telescope, and look for the reflection in that same telescope. By sending the beam out through the telescope, you get a much tighter beam than you would from just the raw laser, and the large telescope gathers 700 thousand times as much light as your eyeball would, making it much easier to see the reflection. (5 m vs. 6 mm squared = 700,000. A fully dilated human pupil is about 6 mm IIRC.)

  14. Well, they did get you to talk about it, so it has been pretty cost effective advertising so far.


  15. KC

    Um . . . I seem to recall that in the late 1960s or early 1970s that some organization – maybe a college or university – did illuminate a spot on the night portion of a quarter moon. I might be mistaken, but I thought a BW photo with a short blurb appeared in a Britannica year book or their annual book of science and the future. I only recall the photo, not an article, so it may not have had a big right up. I also don’t know if the spot was visible with the naked eye.

    I don’t think it was related to the Apollo mission reflectors. First, the spot would have been too large. And second, I remember write-ups about that experiment.

    All this is from memory, and, of course, all errors are my own.

  16. Chip

    I’ve got an old book in French listing real and proposed late 19th Century “modern” inventions and ideas – all illustrated in woodcut lithographic drawings. Somewhere in that book someone has an idea about projecting advertising or important news on the moon! This is long before lasers. (One needs to remember that back then, the electric light of Mr. Edison was THE NEW THING!)

    They also proposed projecting simple messages on nocturnal overcast clouds which might be possible.

  17. Ian


    That sounds extremely suspect. Are you perhaps thinking of the meme that circulated a few years ago about getting everybody on the planet to shine laser pointers at the moon simultaneously in the hopes of lighting it up?

    Somebody did the math, and it turns out that every person on the planet would need 100 million laser pointers to pull it off.

  18. Chip

    BTW – this is total fantasy but if someone ever discovered some kind of weird physics that allowed for light to somehow become enhanced in intensity despite spreading over distance so that a focused image could be projected on the new moon, I’d opt for an image of the planet Jupiter. That would sure confuse people. 😉

  19. tacitus

    Bah! That’s nothing. In one of the novelizations of the BBC scifi series “Red Dwarf” they talk about a ship going on a mission to send bombs into a few dozen carefully chosen suns causing them to go supernova, so they would eventually spell out the phrase “DRINK COCA COLA” when viewed from Earth.

    Now that’s thinking big (and long term!).

  20. PrimeMover

    Thanks Ian & Buzz. That does help me understand the challenge that poses.

  21. Wouldn’t it make more sense to shine at the dark side of a crescent moon?

    And the beams need to spread out, otherwise they’d be too narrow to see.

  22. dre

    Wouldn’t you lose 7/8 of the light? Even worse.

  23. asknot

    Not an astronomer here, but with regards to the GRB, I suspect that they do disperse, or else we’d be observing far fewer of them, and the ones we do see would be frying us from much further away. It’s just the energy is so enormous that we’d get cooked even with the dispersal factored in.

    And if someone really could get a visible signal reflected off the Apollo mirrors at least that should provide plainly obvious proof that we went there and silence those moon hoaxers once and for all.

  24. Lab Lemming: the moon would be too close to the sun in that case. It would be up during the day.

    dre: I was thinking the same thing.

  25. Blaidd Drwg

    Martinus, I was thinking the same thing. I also recall Heinlien mentioning something similar in his story “The Man Who Sold the Moon”, but Clarke’s story was better, IMHO.

  26. Torbjörn Larsson, OM

    They use a 3.5m telescope to receive the returning photons, of which they detect only about 3 per pulse.

    As the eye works as a photon detector (albeit with abysmal efficiency) at low light intensities, ultimately it should be the short integration time that does the eye in, even if the laser wouldn’t be pulsed – not enough signal-to-noise ratio.

  27. shane

    And if someone really could get a visible signal reflected off the Apollo mirrors at least that should provide plainly obvious proof that we went there and silence those moon hoaxers once and for all.

    Nope, obviously placed there by an unmanned robotic probe.

  28. Jeffersonian

    I’ve never had a Rolling Rock but now I’m planning to buy a sixer, hmmm….
    Just kidding, I’m too much of a snob to drink skunky green-bottle crud from which UV has oxidized into tasting like fresh-cut hay.

    There have to be more reasons why the idea wouldn’t work?

  29. defectiverobot

    Any man who can reference the brilliance that is Real Genius deserves a big kiss.


  30. Yeah, it’s 7/8, not 5/6. I fixed it. Weird, I was thinking 7/8 when I wrote that. Not sure why that happened!

  31. Hey BA,
    I am waiting on your “Oklahoma….Doomed” post, after HB2211 was recently passed.

  32. @ silence : yeah, and that guy is still around – me, and I’m a big BA fan (always have been). Had some fun with the idea, as discussed here and on the Wiki site about me. Phil did a bit about my project back then, though he may not remember it – realized what my real intent was, and had some fun with it.

    Jim Downey

  33. KC


    No, it’s a photo I remember. A spot of white on the dark portion of a quarter moon. Caption mentions it was illuminated by laser. This was decades before laser pointers, when the idea of any hand-held self-contained laser was still the stuff of science fiction.

    The time frame would be between 1967 and 1975, closer to around 1970. It will be several weeks before I can get my hands on the book again to verify.

    If anyone has access to Britannica Book of the Year and Britannica book of Science and the Future for that time range, then it should be under the year in review section.

  34. Chip

    Even if the Fonebone Advertising Agency Space Fleet landed on the moon and placed enormous computer controlled, highly reflective solar panels for hundreds of kilometers across the surface, so that the Sun’s rays reflected an advertising slogan back to Earth – the Moon is the size of a aspirin tablet held at arm’s length, so binoculars would still be necessary to read it. Maybe a simple trademark or logo could be seen but not a gigantic paragraph. We tend to psychologically think of the moon in the sky as much larger than it is. 😀

  35. revmonkeyboy

    I only have one word for this, “Spoon”.

    Sorry one more thing, “Gravity is a harsh mistress”.

    My favorite bits from The Tick.

  36. mxracer652

    Rolling Rock is known to us locals as “Pennsylvania Piss”.

    If bad advertising isn’t enough, it’s bad advertising for an equally horrible beer.

  37. Measure

    What if you only wanted to change the color of the moon, just enough for people to notice.

    Would that be doable without a military-grade laser? (You know, maybe a few hundred, powerful commercial grade lasers working in concert?)

  38. Nemo

    It seems like some people don’t really get how big the Moon is (i.e., it’s a whole world), and how far away. They may (or may not) know it intellectually, but they don’t feel it. So they look at something like this, and think, “Why not?” OK, imagine you’re on the Moon, and you want to splash an ad across North America. Yeah, it’s like that.

    This is the same thing that bugged me about the reactions to this story:

    — shows like SNL joking about “blowing up” the Moon. Yeah, ha ha. Not. I’m sorry, but that’s just too stupid to be funny… unless you don’t really get the size of the Moon.

  39. The whole concept is a no-go from the start to even make an exploitive attempt like this towards the Moon. Light by its nature is seen by its reflective power; which is why we see things in the dark when we shine light on them. If you shine a light onto light, you don’t see it, so shining light onto a full Moon would work similar — you just won’t see the reflective properties. The best time, as Phil says, is during first or last quarter when there are portions of the Moon still in darkness. Thank heavens this attempt won’t work in the end, as this pity attempt would ruin the beauty of the face of the Moon.
    John —
    Moon News —

  40. Chas

    Three random-ish thoughts:

    Ian, KC: I remember that picture. As i recall, though, it was of Earth-mounted lasers shooting at one of the Surveyor probes on the Moon’s surface. As you say, late ’60’s.

    Phil: There are two large billboards on I-94, the Tri-State tollway west of Chicago, advertising the moon stunt. Thanks for sparing me having to look at it–I don’t have that much lifetime to spare.

    I recall one of the Moon Hoax guys shining a low-power laser at the moon, not getting any results, and claiming that as “proof” that the missions hadn’t taken placew. If only 3 photons made it back, it explains a lot. Plus they’re dustier and micro-meteorite pitted by now.

  41. Dunc

    Perhaps someone has read Arthur C. Clarke’s 1956 story “Watch This Space”.

    Or Robert Heinlein’s “The Man Who Sold The Moon“, published 1950.

  42. Aerimus


    Whew. For a while there I was beginning to think that I was the only one who thought of The Tick when they first read this!

  43. brian j. parker

    These are the same folks who came up with the stupid “beer ape” viral marketing campaign, too. Their goal is to get people talking about how ridiculous the idea is.

  44. Check out the movie “The Wizard of Speed and Time” – not only is it a great and vastly underrated film which you should be familiar with anyway, but the Jolly Green Wizard manages to write his logo on the Moon with a super power laser!

    (btw The entire movie can be downloaded for free by permission of the director – it’s available as a torrent file.)

  45. Elwood, not only have I been a Mike Jittlov fan since high school, but once upon a time he sent me an email about the Moon Hoax (he was commenting on Al Bean accidentally wiping out the color camera on Apollo 12). I almost passed out. :-)

  46. PrimeMover writes:

    [[Didn’t the astronauts who went to the moon leave behind mirrors that us earthlings use to bounce a laser off them & precisely calculate the distance to the moon??? Phil, how does that work if you say the laser spreads out at such a great distance??]]

    Laser pulses sent to the Moon are detectable with instruments. They are not bright enough to see from Earth’s surface.

  47. JustChris

    Additionally, the mirror is probably very small compared to the wide area that the laser spreads. The instruments will only consider the photons that hit that mirror.

  48. Elwood, thanks for the suggestion! I’ve added “The Wizard of Speed and Time” to my list of stuff to torrent.

    Also, I just want to say that this post is the kind that is my favorite on Bad Astronomy — silly stuff that the media gets wrong, and why. Oh, I read the hard science posts, too, but that usually has to wait until after my 2nd cup of coffee…

  49. Quiet_Desperation

    I dunno… I don’t think the site is supposed to be taken seriously. Is there any word directly from RR on this? I Googled, but only half heartedly.

    And not that I have any love for Rolling Rock, but every time I hear someone who cares enough to piss and moan about a beer, that person invariably favors those weird English or Irish beers that look like dark matter in a mug and will eat holes through the bar top if you spill any.

    Some of us prefer beers that don’t taste and act like battery acid.

    Seriously, several times I have asked self proclaimed beer connoisseurs for a good beer to try, and every single time it turns out to be some horrid, volatile concoction that I am eventually convinced must contain either brimstone or motor oil or both.

    However I will swear by Guinness as a super effective engine cleaner.

    Same thing with you “real chocolate lovers” who only eat the bitterest chocolate that is so dark it absorbs all light and hope from the room. And the hate they heap on milk chocolate, you’d think their parents, siblings, spouses and pets were all killed by drowning in a vat of it.

    Feh. If you are punishing your taste buds to appear sophisticated, you need to re-examine your lifestyle.

    Then again I like those orange circus peanut candies, so what do I know?

  50. Alex Besogonov

    I remember reading an idea about Moon advertisement in Heinlein – spread carbon dust over the large distances.

    It’s easy to do on the Moon – there’s no air friction, so you can shoot carbon dust out of a cannon.

  51. Devo the MAD

    hmmmm, does crow go with beer?

    Anything goes with beer! 😉

  52. Mentionable

    Quoth # Martinus on 05 Mar 2008 at 3:46 pm

    “Perhaps someone has read Arthur C. Clarke’s 1956 story “Watch This Space”. ”

    or Isaac Asimov’s short story ( & the eponymous anthology) ‘Buy Jupiter’ (Isaac asimov, Victor Gollancz publishing, Uk, Granada publishing ltd, 1975. Shizen! Almost as old as me!)

    Wherein super-advanced aliens buy Jupiter from humans for advertising purposes – but miss out on buying Saturn! 😉

    Anything by Asimov, I’d recomend!


    PS. BA does swearing count if its in a foreign language? I hope not! If it does please could you just use the old ‘bad word deleted by the BA’ trick rather than remove the whole post? Please! ( & hey I haven’t even given away what the swear word means ..! Although students of Deutsch may know …)

  53. Devo the MAD

    # Quiet_Desperationon 06 Mar 2008 at 12:53 pm

    “I dunno… I don’t think the site is supposed to be taken seriously. Is there any word directly from RR on this? I Googled, but only half heartedly.

    And not that I have any love for Rolling Rock, but every time I hear someone who cares enough to piss and moan about a beer, that person invariably favors those weird English or Irish beers that look like dark matter in a mug and will eat holes through the bar top if you spill any.

    Some of us prefer beers that don’t taste and act like battery acid.”

    Take nothing seriously!

    Have you tried Coopers Pale Ale from South Australia?

    Or Kirin & Asahi from Nihon -er .. Japan?

    I don’t favor weird English or Irish beers or, I hope, urinate & moan much!

  54. GLMINO

    Hi All,
    You’ve got two weeks for a neet treat, it will work and, may be the most memorable anything you’ve ever seen!
    The laser ( Light Show ) will be transmitted from a communications
    ( with laser light show capabilities! ) satellite.
    This produces an undistorted beem from the lasers.
    Enjoy this one! I hear this a actually a test and will be banned if it
    So, hope it works, so we can see it if only once.
    Looks like a Friday and Saturday night beer party at the very worst.
    Mike in St. Louis

  55. The Tick: The party’s over Chairface!

    Chairface Chippendale: (annoyed) Would you people STOP SAYING THAT!

  56. Bob the Chef

    You commenters suck butt!

    Now that that’s said, would you not prefer to shine the laser at a new moon (or a *dark moon* — whooaaa)? I don’t understand how a half moon would provide “contrast”. If the moon is lit up at all, I would assume that the lit up portion would most likely be brighter than anything projected onto the moon and would in fact reduce the visibility of the projected image.

  57. D-Bo

    I heard today of advertising companies working on ways to get songwriters to get product placement into songs, wouldnt it be possible to accomplish the moonvertising from a satellite equipped to do so. Maybe not rolling rocks attempt to create controversey, but a real global corporation like the windows butterfly or the swoosh. There is ways to accomplish this feat from a satellite to our satellite….

  58. TrueBeerLover

    The ad campaign is better than the beer. The beer should be called Rolling Rock p–s water.
    As for the laser image on the moon it, is impossible; but that is really not the point. Any ad campaign wants to get you to think about the product and hopefully buy it. Since people are already talking about the rolling rock beer logo on the moon the campaign has been a success regardless of whether or not the whole thing is a hoax — which I think it is. So the ad campaign is effective and creative but the beer sucks.

  59. Moonanites

    Seriously, you are 100% correct about their website. The flash is painfully slow and then it started eating all my CPU. It was so slow that my daughter was learning to read faster than it was printing the text.

    Anyhow, what makes them think that they are going to put a message on the moon when they cant even successfully put the message on a website?

  60. CaliJess

    Wow. As a marketer I can ususally go with the flow on anything, hence my interest in said ploy. But WOW you are right, what a terrible website. I can’t even figure out what time to go look at the moon to fall for their silly scheme. Pathetic. Its sad that they can spend all that $$ on look and have no content.

  61. Bill

    one thing for sure..all you geeks have wayyyyyyyyyy too much time on your hands. No wonder you don’t get laid

  62. Scott

    Too bad they couldn’t turn the moon into a big Obama button.

  63. SuperACG

    James Rolfe (AKA: The Angry Video Game Nerd) drinks Rolling Rock. That alone increased my awareness of the beer. Perhaps he should be in the commercials…

  64. damian

    I don’t know if anyone has mentioned this, but a Google search for “rolling+rock+moon” leads to THIS site at #1, and the official Rolling Rock site #2.


  65. Rock Fan

    OmG! I am so excited..what time does the moon come up?

  66. Joe

    I think its a cool idea. If it works, everyone else will learn to like it also, even all you lame ass critics.

  67. Rockin' Randy

    To all of you; Beer is an art. And like all art, it is subjective. There are thousands of beers made around the world and all are different from one another. Just like you and me, we’re all different. You don’t have to like everybody, but you do have to respect everybody. It’s the same for beer. You may like one beer over another, but that does not make the beer you don’t like a bad beer. As for the Moon, it ‘s a natual wonder for all behold. It is not a billboard. So enjoy the beer of your choice. Stop wasting time and energy carping about beer you don’t like. And watch the wonders that are given to us in the heavens above.

    “Beer is proof that God loves us and wants us to be happy” Benjamin Franklin

  68. Jack

    Phil, reality changes as we get smarter and improve things like technology. If you were as smart as you seem to act, then you’d understand that. Perhaps it won’t work, but its a cool idea and if it does work, companies will do battle over who gets to advertise on the moon next.

  69. Rock Fan

    Damn, I got drunk and missed it. Did anybody see it? Was it cool? I bet it was awesome. If anybody has a pic post please. Ill be back later my head hurts.

  70. Mike

    If you drink enough beers, and hold your Rolling rock up with the moon behind the bottle you can see the R.R. logo….. It works.


  71. Pussy Lips

    I missed it. What happened? It probably didn’t work but it’d be so cool to see it if it did. Someone tell me what happened!!!!!!!

  72. Joe

    I doubt it worked but that would be awesome to see. I can’t find any info on their attempt. Can someone clue the rest of us in, please?

  73. Chris

    You’re an idiot, it’s just an advertising campaign, and besides, how is it Rolling Rocks’ problem that you have a lousy internet connection and computer! Their website runs great on mine, and I think it’s awesome!

  74. KC

    I was able to find the book with the photo I remembered. It turned out to be a photo of the crescent *earth* taken by the Surveyor 7 lander. In the dark portion was two dots of lights from lasers beamed at the Surveyor 7 landing site from two U.S. observatories. This is on page 236 under Astronautics in the 1969 Britannica Yearbook of Science and the Future.

    Knowing this, it was easy to do a web search. Sure enough, the photo I remembered can be seen here:

    According to this web site, these were 2-Watt Argon lasers, one at the Table Mountain and the other at Kitt Peak.

    So what I remembered was *not* illumination of the night-portion of the moon, but, I humbly submit, is just as cool.

  75. Not to mention that if someone did that successfully (advertise with the moon as such) it would probably violate the outer space treaty and they would deserve to be put in Jail for it. It would be like toilet-papering the grand canyon as a publicity stunt. Even talking about it make me angry.

    All in all its pretty dumb.

  76. Roger

    There’s an easier way. Launch a satellite and shot the laser from it.



  78. Chelle

    I must admit you got me. I actually thought you could shine a bean on thee large, seen at millions of different angles, and mighty far away moon. The only moon you will shine an ad on will be the moon sticking out of the advertisement ON the billboard itself. LOVED it anyway :)

  79. Roberto

    I appreciate that many of you think this was an effective advertising scheme because it got us “talking about it.” But frankly, except for the first few minutes when I wondered if it was actually possible to do what Rolling Rock claimed it was going to do, after I figured out that it was a joke, I stopped caring. I don’t drink their beer, and never will. And even if they COULD beam their logo to the moon, I still wouldn’t drink their beer.

  80. Darth Borehd

    I was thinking about how you might make something appear to be on the moon. Perhaps if they aimed the lasers so that they intersected at certain points and had a lot of dust in the air, They could create the optical illusion of something being displayed on the moon. Or maybe instead of lasers they could make some kind of display with search lights??

  81. Walter

    What if a laser was stationed at the Earth-Moon Langrange 1 point?
    This is a stable point only about 60000 miles from the moon.

  82. Chris

    Of course this would not work, for would’nt a laser melt the green cheese that the moon is made of? (Tee Hee)

    On the ‘fake’ moon landing…is the ‘flag’ that was planted still there and if so is it visable through powerful telescopes from earth? Would this either prove the moon landing as fact or expose it as a hoax?

  83. Chris

    P.S. Why is society so desperate to occupy the moon, mars or any other celestial object other than Earth. We as a collective society can not even manage this planet to keep pollution, political strife, and a harmonious balance in check. Why spread our ‘viral’ ways further. We should be more concentrated on ‘SAVING’ our planet, than spreading our ‘crap’ into outer space!!!!!!!!

  84. Mike

    Here is perhaps the simplest way to see the utter infeasibility of the concept of lighting the full moon in a way that would be visible to the naked eye, requiring no calculations and no knowledge of the moon’s albedo: The light that we normally see coming from the full moon is reflected from the sunlight that is falling on the entire face of the moon, which has a surface area comparable to a largish continent on Earth (about 2000 mi diameter). Therefore, to significantly change the light we see reflected back from the moon’s surface, even if the light that we send there is focused so that 100% of it falls on the moon, the amount of light power that we would have to project onto the moon (for a period sustained long enough to see) would have to be comparable to the amount of power that would be produced if one were to cover all of North America with high-efficiency solar panels, or, more simply, mirrors reflecting the sun’s image onto the moon. At the Earth’s distance from the moon, North America looks about as large as the sun, so an image of the sun could just barely fit into a North-America-sized mirror. Or, another way to think about the problem: From the point of view of someone standing on the moon (anywhere on the area to be lit), the source of light on Earth would have to look about as bright to them as the sun looks to us. Think about how much power it would take to make the Earth appear as bright as the sun!

  85. How do you feel about new talks to use shadows to advertise on the moon?


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