# If we had the inclination, could we nuke the moon out of its orbit? **URL:** \ **Category:** Great Debates\ **Created:** [February 7, 2004, 1:40am UTC](https://boards.straightdope.com/t/if-we-had-the-inclination-could-we-nuke-the-moon-out-of-its-orbit/227930 "2004-02-07T01:40:55Z")\ **Posts on this page:** 19\ **Page:** 2
**Author:** ![eburacum45](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/eburacum45/32/8690_2.png) [@eburacum45](https://boards.straightdope.com/u/eburacum45)\ **Post date:** [February 8, 2004, 12:40am UTC](https://boards.straightdope.com/t/if-we-had-the-inclination-could-we-nuke-the-moon-out-of-its-orbit/227930/21 "2004-02-08T00:40:53Z")
Here is an earlier thread about [Blowing up the Moon](http://boards.straightdope.com/sdmb/showthread.php?threadid=173243&highlight=moon); it appears it would take 10[sup]13[/sup] megatons to blow up the moon, or to do it on the cheap, 10[sup]7[/sup] megatons to bring it within the Roche limit, and see it disintegrate under the influence of tidal forces into a ring like Saturn’s. That is ten million one-megaton bombs. Quite a few. * * * SF worldbuilding at [http://www.orionsarm.com/main.html](http://www.orionsarm.com/main.html) ---
**Author:** ![RickJay](https://avatars.discourse-cdn.com/v4/letter/r/bb73d2/32.png) [@RickJay](https://boards.straightdope.com/u/RickJay)\ **Post date:** [February 8, 2004, 5:49am UTC](https://boards.straightdope.com/t/if-we-had-the-inclination-could-we-nuke-the-moon-out-of-its-orbit/227930/22 "2004-02-08T05:49:20Z")
> [@eburacum45](#): > > That is ten million one-megaton bombs. > > Quite a few. And again, that’s only assuming ALL the force of your bombs is vectored in the direction you want, which obviously would not be the case if you just piled up all your bombs on the surface of the Moon and set them off. In fact, you would need many, many more bombs than that, at least five times as many. ---
**Author:** ![peteau](https://avatars.discourse-cdn.com/v4/letter/p/b19c9b/32.png) [@peteau](https://boards.straightdope.com/u/peteau)\ **Post date:** [February 8, 2004, 2:13pm UTC](https://boards.straightdope.com/t/if-we-had-the-inclination-could-we-nuke-the-moon-out-of-its-orbit/227930/23 "2004-02-08T14:13:30Z")
Ok, so our Moon is too big. What about Mars’ moons? They are much smaller, somewhere around ~20km iirc. Could we give them a nudge into a decaying orbit and crash them into the planet? What affect would a ~20km impact have on Mars? -Pete. ---
**Author:** ![Uncivil](https://avatars.discourse-cdn.com/v4/letter/u/ccd318/32.png) [@Uncivil](https://boards.straightdope.com/u/Uncivil)\ **Post date:** [February 8, 2004, 2:24pm UTC](https://boards.straightdope.com/t/if-we-had-the-inclination-could-we-nuke-the-moon-out-of-its-orbit/227930/24 "2004-02-08T14:24:50Z")
> [@peteau](#): > > Ok, so our Moon is too big. What about Mars’ moons? > > They are much smaller, somewhere around ~20km iirc. Could we give them a nudge into a decaying orbit and crash them into the planet? What affect would a ~20km impact have on Mars? > > -Pete. Can I change this question please? Out of sheer vindictiveness, I’d like to know what would happen if we nudged Phobos out of orbit and collided it with France. 😃 (I’d just like to point out that I’m not really anti-French, but as a brit I’m culturally obliged to slate them at every opportunity. And even occasionally moon them). ---
**Author:** ![RickJay](https://avatars.discourse-cdn.com/v4/letter/r/bb73d2/32.png) [@RickJay](https://boards.straightdope.com/u/RickJay)\ **Post date:** [February 8, 2004, 3:20pm UTC](https://boards.straightdope.com/t/if-we-had-the-inclination-could-we-nuke-the-moon-out-of-its-orbit/227930/25 "2004-02-08T15:20:23Z")
> [@Uncivil](#): > > Can I change this question please? Out of sheer vindictiveness, I’d like to know what would happen if we nudged Phobos out of orbit and collided it with France. 😃 Regrettably, you would almost certainly annihilate human civilization and all life on Earth. Phobos is quite a bit larger than that nasty comet in “Deep Impact.” ---
**Author:** ![Finagle](https://avatars.discourse-cdn.com/v4/letter/f/b19c9b/32.png) [@Finagle](https://boards.straightdope.com/u/Finagle)\ **Post date:** [February 8, 2004, 3:25pm UTC](https://boards.straightdope.com/t/if-we-had-the-inclination-could-we-nuke-the-moon-out-of-its-orbit/227930/26 "2004-02-08T15:25:22Z")
Just thought I’d point out that the moon is peppered with craters from the impact of big-ass Armageddon-sized rocks. If none of those were sufficient to deflect the moon substantially, then it’s doubtful we’ve got anything that would do the job. ---
**Author:** ![Ludovic](https://avatars.discourse-cdn.com/v4/letter/l/7ab992/32.png) [@Ludovic](https://boards.straightdope.com/u/Ludovic)\ **Post date:** [February 9, 2004, 6:11am UTC](https://boards.straightdope.com/t/if-we-had-the-inclination-could-we-nuke-the-moon-out-of-its-orbit/227930/27 "2004-02-09T06:11:55Z")
I think we are on to something with the mass accelerator. We could build several mobile nuclear factories that crushed rocks into small chunks and ejected them in the right direction at several miles per second. That will kill two birds with one (heheheh) stone. Not only will the moon’s orbit change, its mass will also diminish, making further pushing easier…voila 😉 ---
**Author:** ![Panzar](https://avatars.discourse-cdn.com/v4/letter/p/8e8cbc/32.png) [@Panzar](https://boards.straightdope.com/u/Panzar)\ **Post date:** [February 9, 2004, 3:31pm UTC](https://boards.straightdope.com/t/if-we-had-the-inclination-could-we-nuke-the-moon-out-of-its-orbit/227930/28 "2004-02-09T15:31:39Z")
I suggest leaving the moon where it is. Without it the earth would no longer be tilting approximately 23.5 degrees. Instead of a nice stable climate we would get frequent dramatic changes. It is possible that we owe our very existance to the moon’s effects. And now you want to get rid of it. That’s some gratitude. 🙂 ---
**Author:** ![BabaBooey](https://avatars.discourse-cdn.com/v4/letter/b/dfb087/32.png) [@BabaBooey](https://boards.straightdope.com/u/BabaBooey)\ **Post date:** [February 9, 2004, 8:14pm UTC](https://boards.straightdope.com/t/if-we-had-the-inclination-could-we-nuke-the-moon-out-of-its-orbit/227930/29 "2004-02-09T20:14:09Z")
Let’s just write a massive “Chairface” on its surface and call it a day… ---
**Author:** ![Dewey\_Cheatem\_Undhow](https://avatars.discourse-cdn.com/v4/letter/d/13edae/32.png) [@Dewey\_Cheatem\_Undhow](https://boards.straightdope.com/u/Dewey_Cheatem_Undhow)\ **Post date:** [February 9, 2004, 8:37pm UTC](https://boards.straightdope.com/t/if-we-had-the-inclination-could-we-nuke-the-moon-out-of-its-orbit/227930/30 "2004-02-09T20:37:57Z")
> [@RickJay](#): > > > [@Uncivil](#): > > > > Can I change this question please? Out of sheer vindictiveness, I’d like to know what would happen if we nudged Phobos out of orbit and collided it with France. > > Regrettably, you would almost certainly annihilate human civilization and all life on Earth. Phobos is quite a bit larger than that nasty comet in “Deep Impact.” Then can we dig up France and fling it at Phobos? 😃 ---
**Author:** ![peteau](https://avatars.discourse-cdn.com/v4/letter/p/b19c9b/32.png) [@peteau](https://boards.straightdope.com/u/peteau)\ **Post date:** [February 10, 2004, 3:57am UTC](https://boards.straightdope.com/t/if-we-had-the-inclination-could-we-nuke-the-moon-out-of-its-orbit/227930/31 "2004-02-10T03:57:00Z")
> [@Dewey Cheatem Undhow](#): > > Then can we dig up France and fling it at Phobos? 😃 The French heard your threat and are already preparing to surrender. ---
**Author:** ![Sam\_Stone](https://avatars.discourse-cdn.com/v4/letter/s/ecccb3/32.png) [@Sam\_Stone](https://boards.straightdope.com/u/Sam_Stone)\ **Post date:** [February 10, 2004, 4:15am UTC](https://boards.straightdope.com/t/if-we-had-the-inclination-could-we-nuke-the-moon-out-of-its-orbit/227930/32 "2004-02-10T04:15:17Z")
> [@](#): > > I suggest leaving the moon where it is. > > Without it the earth would no longer be tilting approximately 23.5 degrees. Instead of a nice stable climate we would get frequent dramatic changes. It is possible that we owe our very existance to the moon’s effects. Where do you get that idea? The moon doesn’t keep the earth tilted - conservation of angular momentum ensures that the Earth will stay exactly the way it is whether the moon is there or not. My understanding is that the Earth is tilted because of a collision early on when it was being formed or shortly thereafter. What we would lose are tides. Without tides, I wonder what would happen to features like the gulf stream? ---
**Author:** ![E72521](https://avatars.discourse-cdn.com/v4/letter/e/dbc845/32.png) [@E72521](https://boards.straightdope.com/u/E72521)\ **Post date:** [February 10, 2004, 5:34am UTC](https://boards.straightdope.com/t/if-we-had-the-inclination-could-we-nuke-the-moon-out-of-its-orbit/227930/33 "2004-02-10T05:34:09Z")
NOVA did an episode on the moon not too long ago, but I was kinda dozing on the couch through a lot of it. I do remember these key points: The moon was once an orbiting planet that collided with earth. It wasn’t a direct hit, it just sort of grazed us. The earth and the moon exchanged material. This collision caused the earth to wobble. Early on the moon took up most of the sky. The moon moves about two inches a year away from the earth. The earth still wobbles from this collision. The farther the moon moves away from the earth, the less the earth wobbles. Eventually the moon will be far enough away that the earth will no longer wobble. That will be the end of the seasons. That will be the end of life on earth. Life probably existed when this collision occurred, but it is not clear if it originated on the runaway planet we call the moon, or it started here. Life on earth is as dependent on the moon as it is on the sun. This should make every Wiccan happy. (OK, they didn’t really address neopaganism on NOVA) If you’re really interested, you might want to check either NOVA’s or PBS’s web sites for better information than I just pulled out of my clouded memory. ---
**Author:** ![BobLibDem](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/boblibdem/32/3149_2.png) [@BobLibDem](https://boards.straightdope.com/u/BobLibDem)\ **Post date:** [February 10, 2004, 1:16pm UTC](https://boards.straightdope.com/t/if-we-had-the-inclination-could-we-nuke-the-moon-out-of-its-orbit/227930/34 "2004-02-10T13:16:21Z")
The wobbles would be slight deviations in the earth’s tilt- losing the moon would not magically reset the earth’s axis to be 90 degrees from the orbital path. None of the planets’ axes are plumb to their orbits, whether they have moons or not. ---
**Author:** ![Uncivil](https://avatars.discourse-cdn.com/v4/letter/u/ccd318/32.png) [@Uncivil](https://boards.straightdope.com/u/Uncivil)\ **Post date:** [February 10, 2004, 1:29pm UTC](https://boards.straightdope.com/t/if-we-had-the-inclination-could-we-nuke-the-moon-out-of-its-orbit/227930/35 "2004-02-10T13:29:07Z")
> [@Sam Stone](#): > > Where do you get that idea? The moon doesn’t keep the earth tilted - conservation of angular momentum ensures that the Earth will stay exactly the way it is whether the moon is there or not. My understanding is that the Earth is tilted because of a collision early on when it was being formed or shortly thereafter. According to some of the latest research, a planet’s angle of inclination can vary enourmously over very long periods of time. Scientists think that Mars was once tilted 90 degrees over, and that the strong influence of the moon’s gravity stops that happening to Earth. The Earth wobbles slightly on its axis, but its nothing compared to the other planets in the solar system. ---
**Author:** ![Uncivil](https://avatars.discourse-cdn.com/v4/letter/u/ccd318/32.png) [@Uncivil](https://boards.straightdope.com/u/Uncivil)\ **Post date:** [February 10, 2004, 1:35pm UTC](https://boards.straightdope.com/t/if-we-had-the-inclination-could-we-nuke-the-moon-out-of-its-orbit/227930/36 "2004-02-10T13:35:53Z")
> [@E72521](#): > > The earth still wobbles from this collision. The farther the moon moves away from the earth, the less the earth wobbles. Eventually the moon will be far enough away that the earth will no longer wobble. That will be the end of the seasons. That will be the end of life on earth. Simply wrong I’m afraid. The seasons aren’t caused by wobbles in the Earth’s orbit. They are caused because the Earth’s axis of rotation is inclined about 23 degrees to the orbital plane. In the north’s summer, the norhtern hemisphere points towards the sun, so the days are longer. More heat is absorbed by the surface, so its hotter. The moon stabilises the Earth’s rotation, so over millions of years the seasons haven’t varied much. There is a 41,000 year cycle called precession, but the effect is tiny. If the moon wasn’t there, its possible that the angle of inclination could vary enourmously. If it reached 90 degrees, one side of the Earth would point towards the sun for 6 months while the other half froze. Not good for life, which is why the moon is so important. ---
**Author:** ![Revtim](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/revtim/32/1042_2.png) [@Revtim](https://boards.straightdope.com/u/Revtim)\ **Post date:** [February 10, 2004, 2:49pm UTC](https://boards.straightdope.com/t/if-we-had-the-inclination-could-we-nuke-the-moon-out-of-its-orbit/227930/37 "2004-02-10T14:49:41Z")
> [@E72521](#): > > NOVA did an episode on the moon not too long ago, but I was kinda dozing on the couch through a lot of it. I do remember these key points: > > The moon was once an orbiting planet that collided with earth. It wasn’t a direct hit, it just sort of grazed us. The earth and the moon exchanged material. I thought the latest theory was that a 3rd Mars-sized object hit the Earth, ejecting from the Earth the matter that made up the moon. Was that what you meant, or was Nova presenting a different theory? ---
**Author:** ![Panzar](https://avatars.discourse-cdn.com/v4/letter/p/8e8cbc/32.png) [@Panzar](https://boards.straightdope.com/u/Panzar)\ **Post date:** [February 10, 2004, 6:46pm UTC](https://boards.straightdope.com/t/if-we-had-the-inclination-could-we-nuke-the-moon-out-of-its-orbit/227930/38 "2004-02-10T18:46:47Z")
> [@Sam Stone](#): > > Where do you get that idea? The moon doesn’t keep the earth tilted - conservation of angular momentum ensures that the Earth will stay exactly the way it is whether the moon is there or not. My understanding is that the Earth is tilted because of a collision early on when it was being formed or shortly thereafter. I got this idea from our prominent scientists through such medias as books, television and various Internet sites. This is a subject that I was interested in and I did read a lot about it. I attach a quote from [http://www.bbc.co.uk/radio4/science/nature\_20031027.shtml](http://www.bbc.co.uk/radio4/science/nature_20031027.shtml) > [@](#): > > As planets in our solar system spin in their elliptical orbits around the Sun , they do so through an axis of rotation which is at an angle to the upright rather like a top spinning (called obliquity). The planets are subject to the gravitational pull of all the other planets which varies depending on how close they are to them. The net effect of all this is to alter the angle of tilt of the spinning planet chaotically. Sometimes it may be 0 degrees, in which case the planet is rotating upright with the equator directly facing the sun and there is equal day and night. > > At other times it could be as much as 90 degrees in which case the North Pole is pointing towards the sun. For most planets this variation is chaotic, leading to huge climatic change. > > Our Moon is very special in the solar system in that it is very large compared to its partner planet and its gravitational pull is dominant on the Earth, making that from other large planets like Jupiter almost negligible. This has had a profound effect on evolution for it keeps the Earth’s tilt almost constant at 23.5 degrees - giving climatic stability for life to evolve. There have been no chaotic and wild changes in the Earth’s climate and life has been able to adapt and diversify to different habitats over millions of years without for instance deserts turning into ice caps. > > We owe our seasons and migration to the fact that the Earth is tilted at 23.5. > > So next time you look up at the Moon remember we may not be here today without it. ---
**Author:** ![Uncivil](https://avatars.discourse-cdn.com/v4/letter/u/ccd318/32.png) [@Uncivil](https://boards.straightdope.com/u/Uncivil)\ **Post date:** [February 10, 2004, 8:18pm UTC](https://boards.straightdope.com/t/if-we-had-the-inclination-could-we-nuke-the-moon-out-of-its-orbit/227930/39 "2004-02-10T20:18:27Z")
Thanks for the link Panzar, thats what I was trying to explain. [Previous page](https://boards.straightdope.com/t/if-we-had-the-inclination-could-we-nuke-the-moon-out-of-its-orbit/227930.md?page=1)