# Is the moon really hollow and other moon observations. **URL:** \ **Category:** Factual Questions\ **Created:** [September 5, 2017, 11:55pm UTC](https://boards.straightdope.com/t/is-the-moon-really-hollow-and-other-moon-observations/795601 "2017-09-05T23:55:39Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Silver\_lining](https://avatars.discourse-cdn.com/v4/letter/s/aca169/32.png) [@Silver\_lining](https://boards.straightdope.com/u/Silver_lining)\ **Post date:** [September 5, 2017, 11:55pm UTC](https://boards.straightdope.com/t/is-the-moon-really-hollow-and-other-moon-observations/795601/1 "2017-09-05T23:55:39Z")
Is the moon really hollow? Test says the moon is older than the earth but is it hollowed out? Perhaps. In two test crashes from the Applo missions, the moon rang like a bell for a while, then on a second larger forced crash like a gong according to the astronaut. For some reason, the craters on the moon whether they are very large or small all seem to have close to the same amount of depth in them. That just does not make sense as the larger the asteroid or comet the deeper the depth should be from impact. What do you make of this? To further blow your mind the moon has several rare things about it. It’s in the same rotational orbit as the earth meaning there is a side of the moon we never see ( The dark side of the moon ) and is the perfect distance so it appears to be the exact same size as the sun. ---
**Author:** ![Ethilrist](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ethilrist/32/4604_2.png) [@Ethilrist](https://boards.straightdope.com/u/Ethilrist)\ **Post date:** [September 5, 2017, 11:56pm UTC](https://boards.straightdope.com/t/is-the-moon-really-hollow-and-other-moon-observations/795601/2 "2017-09-05T23:56:44Z")
Um. Cite? ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [September 5, 2017, 11:59pm UTC](https://boards.straightdope.com/t/is-the-moon-really-hollow-and-other-moon-observations/795601/3 "2017-09-05T23:59:53Z")
Yes, it rang like a bell, but it rang like a solid bell, not like a hollow bell. That’s why they did those tests, to see what it was like inside, and what they saw was not at all consistent with it being hollow. Craters aren’t all the same depth, and I don’t know where you got that impression. ---
**Author:** ![snfaulkner](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/snfaulkner/32/433_2.png) [@snfaulkner](https://boards.straightdope.com/u/snfaulkner)\ **Post date:** [September 6, 2017, 12:04am UTC](https://boards.straightdope.com/t/is-the-moon-really-hollow-and-other-moon-observations/795601/4 "2017-09-06T00:04:14Z")
Tidal locking isn’t all that rare. Or mind blowing. Where did you get all this nonsense? ---
**Author:** ![Maggie\_the\_Ocelot](https://avatars.discourse-cdn.com/v4/letter/m/df705f/32.png) [@Maggie\_the\_Ocelot](https://boards.straightdope.com/u/Maggie_the_Ocelot)\ **Post date:** [September 6, 2017, 12:07am UTC](https://boards.straightdope.com/t/is-the-moon-really-hollow-and-other-moon-observations/795601/5 "2017-09-06T00:07:45Z")
Every Doctor Who fan knows that the moon is actually an egg. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [September 6, 2017, 12:16am UTC](https://boards.straightdope.com/t/is-the-moon-really-hollow-and-other-moon-observations/795601/6 "2017-09-06T00:16:05Z")
The aforementioned seismic experiments suggest the existence of a [partially liquid outer core](https://www.nasa.gov/topics/moonmars/features/lunar_core.html) inside the moon. (The space is all filled up, of course, as you would expect under the effect of gravity.) ---
**Author:** ![Exapno\_Mapcase](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/exapno_mapcase/32/1051_2.png) [@Exapno\_Mapcase](https://boards.straightdope.com/u/Exapno_Mapcase)\ **Post date:** [September 6, 2017, 12:17am UTC](https://boards.straightdope.com/t/is-the-moon-really-hollow-and-other-moon-observations/795601/7 "2017-09-06T00:17:11Z")
> [@Silver\_lining](#): > > Test says the moon is older than the earth … Test says? What do you mean by this? (If it’s a friend of yours named Test, just give him a whack upside the head whenever he says things like this.) ---
**Author:** ![Evan\_Drake](https://avatars.discourse-cdn.com/v4/letter/e/b487fb/32.png) [@Evan\_Drake](https://boards.straightdope.com/u/Evan_Drake)\ **Post date:** [September 6, 2017, 12:20am UTC](https://boards.straightdope.com/t/is-the-moon-really-hollow-and-other-moon-observations/795601/8 "2017-09-06T00:20:08Z")
There was a BBC documentary about the moon many decades ago called ‘[**Clangers**](https://en.wikipedia.org/wiki/Clangers)’ Maybe such a name made you think of the moon ringing. ---
**Author:** ![burpo\_the\_wonder\_mutt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/burpo_the_wonder_mutt/32/365_2.png) [@burpo\_the\_wonder\_mutt](https://boards.straightdope.com/u/burpo_the_wonder_mutt)\ **Post date:** [September 6, 2017, 12:27am UTC](https://boards.straightdope.com/t/is-the-moon-really-hollow-and-other-moon-observations/795601/9 "2017-09-06T00:27:51Z")
No, the world is hollow and I have touched the sky. ---
**Author:** ![dtilque](https://avatars.discourse-cdn.com/v4/letter/d/d6d6ee/32.png) [@dtilque](https://boards.straightdope.com/u/dtilque)\ **Post date:** [September 6, 2017, 12:35am UTC](https://boards.straightdope.com/t/is-the-moon-really-hollow-and-other-moon-observations/795601/10 "2017-09-06T00:35:23Z")
> [@snfaulkner](#): > > Tidal locking isn’t all that rare. Or mind blowing. Where did you get all this nonsense? It’d actually be unusual if the moon _were not_ tidally locked. I recently wondered how long it would take to become tidally locked and found some approximate equations on [Wikipedia](https://en.wikipedia.org/wiki/Tidal_locking). Plugging in some numbers and being even more approximate (i.e. I just added and subtracted exponents), I found that if the Moon began at 100,000 Km away (one quarter of its current distance), it would tidally lock in only about 10,000 years. But the function is dependent on the 6th power of the distance, so moving it in or out a bit changes that number rather quickly. ---
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [September 6, 2017, 12:49am UTC](https://boards.straightdope.com/t/is-the-moon-really-hollow-and-other-moon-observations/795601/11 "2017-09-06T00:49:52Z")
> [@Silver\_lining](#): > > [snip] … then on a second larger forced crash like a gong according to the astronaut … [snap] How did the astronaut survive to tell this tale? … ---
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [September 6, 2017, 1:18am UTC](https://boards.straightdope.com/t/is-the-moon-really-hollow-and-other-moon-observations/795601/12 "2017-09-06T01:18:48Z")
Well, every forced crash has a _cough_ **Silver lining**. ---
**Author:** ![watchwolf49](https://avatars.discourse-cdn.com/v4/letter/w/e9c0ed/32.png) [@watchwolf49](https://boards.straightdope.com/u/watchwolf49)\ **Post date:** [September 6, 2017, 1:29am UTC](https://boards.straightdope.com/t/is-the-moon-really-hollow-and-other-moon-observations/795601/13 "2017-09-06T01:29:40Z")
> [@Lucas\_Jackson](#): > > Well, every forced crash has a _cough_ **Silver lining**. … but every silver lining has a touch of grey … ---
**Author:** ![burpo\_the\_wonder\_mutt](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/burpo_the_wonder_mutt/32/365_2.png) [@burpo\_the\_wonder\_mutt](https://boards.straightdope.com/u/burpo_the_wonder_mutt)\ **Post date:** [September 6, 2017, 1:34am UTC](https://boards.straightdope.com/t/is-the-moon-really-hollow-and-other-moon-observations/795601/14 "2017-09-06T01:34:44Z")
^ Do you two need a tenor? _ahem_ _Oh, every time it rains, it rains pennies from heaven._ ---
**Author:** ![Peter\_Morris](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/peter_morris/32/359_2.png) [@Peter\_Morris](https://boards.straightdope.com/u/Peter_Morris)\ **Post date:** [September 6, 2017, 1:39am UTC](https://boards.straightdope.com/t/is-the-moon-really-hollow-and-other-moon-observations/795601/15 "2017-09-06T01:39:02Z")
> [@Maggie\_the\_Ocelot](#): > > Every Doctor Who fan knows that the moon is actually an egg. But every James Bond fan knows that The World Is Not Un Oeuf. ---
**Author:** ![Xema](https://avatars.discourse-cdn.com/v4/letter/x/9de053/32.png) [@Xema](https://boards.straightdope.com/u/Xema)\ **Post date:** [September 6, 2017, 2:23am UTC](https://boards.straightdope.com/t/is-the-moon-really-hollow-and-other-moon-observations/795601/16 "2017-09-06T02:23:05Z")
> [@Silver\_lining](#): > > … it appears to be the exact same size as the sun. No. The angular sizes of the moon and sun are close, but certainly not exactly the same. One clue is that some eclipses are annular: the moon’s angular size is insufficient to cover the sun, so at peak eclipse the sun appears as a thin ring surrounding the moon. ---
**Author:** ![Grey](https://avatars.discourse-cdn.com/v4/letter/g/b782af/32.png) [@Grey](https://boards.straightdope.com/u/Grey)\ **Post date:** [September 6, 2017, 2:45am UTC](https://boards.straightdope.com/t/is-the-moon-really-hollow-and-other-moon-observations/795601/17 "2017-09-06T02:45:12Z")
> [@watchwolf49](#): > > … but every silver lining has a touch of grey … Keep me the hell out of this. 🙂 ---
**Author:** ![cmyk](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/cmyk/32/3353_2.png) [@cmyk](https://boards.straightdope.com/u/cmyk)\ **Post date:** [September 6, 2017, 8:04am UTC](https://boards.straightdope.com/t/is-the-moon-really-hollow-and-other-moon-observations/795601/18 "2017-09-06T08:04:44Z")
Of course the moon is hollow. And it’s filled with helium — how else do you think it stays up in the sky? ---
**Author:** ![Lucas\_Jackson](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lucas_jackson/32/303_2.png) [@Lucas\_Jackson](https://boards.straightdope.com/u/Lucas_Jackson)\ **Post date:** [September 6, 2017, 8:56am UTC](https://boards.straightdope.com/t/is-the-moon-really-hollow-and-other-moon-observations/795601/19 "2017-09-06T08:56:53Z")
> [@burpo\_the\_wonder\_mutt](#): > > ^ Do you two need a tenor? _ahem_ > > _Oh, every time it rains, it rains pennies from heaven._ Every time it rains, it rains panties from heaven. ---
**Author:** ![kayaker](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kayaker/32/441_2.png) [@kayaker](https://boards.straightdope.com/u/kayaker)\ **Post date:** [September 6, 2017, 10:47am UTC](https://boards.straightdope.com/t/is-the-moon-really-hollow-and-other-moon-observations/795601/20 "2017-09-06T10:47:21Z")
Bull. A hollow cheese structure of that immense size would collapse. Or melt. [Next page](https://boards.straightdope.com/t/is-the-moon-really-hollow-and-other-moon-observations/795601.md?page=2)