I plan to destroy the moon. What effect would this have on the earth?

SHARE I plan to destroy the moon. What effect would this have on the earth?

Dear Cecil: I thought I should consult you first before I went ahead with my plan to destroy the moon. My questions to you are simple, or maybe not. Could the earth (and the scum who inhabit it) survive without the moon? Would the lack of its gravitational sway cause any substantial damage aside from pissing off a lot of surfers? Would everyone all of a sudden have one serious mood swing? Just how important is this moving target? I won’t begin operations until I hear from you first. Greg Angelone, via the Internet

001027.gif

Illustration by Slug Signorino

Cecil replies:

Destroying major planetary bodies shows a lack of maturity, Greg. There are better ways of expressing your anger. Can’t you just hold your breath until you turn blue?

At the moment I can’t give you a definite answer on the effects of destroying the moon. The parties I’ve consulted so far think that either (a) nothing much will happen or (b) it’ll be the end of the world. I’m working on getting this pinned down.

One question: How do you propose to have the moon taken out? Obviously, if island-size chunks will be raining down on Cleveland, there’s going to be a significant negative impact (on Cleveland, anyway). In order not to mess up our answer, however, let’s assume you’re thinking of a simple process of vaporization.

My initial thoughts regarding the impact of lunar destruction were as follows:

(1) No more big tides, surfing, etc. Tides wouldn’t disappear entirely, since the sun would continue to tug on the oceans, causing high tides of diminished amplitude at noon and midnight. But, as one early consultant pointed out, it’s a safe bet the bottom would fall out of the tourist trade in the Bay of Fundy, noted for its tidal extremes.

(2) Dogs would have to bay at, I dunno, Alpha Centauri.

(3) Much darker at night. Duh, you say, but a fair amount of nocturnal activity among the lower orders is pegged to moonlight.

(4) The famous children’s book Goodnight Moon would require considerable rethinking.

(5) One less thing to rhyme with June.

(6) We’d have to think up another name for shoving your naked butt out the car window at passersby.

(7) No more eclipses. Incidentally, the next partial eclipse of the sun visible in North America will occur this coming Christmas Day. Wouldn’t want to miss that, so please hold off on the destruction of the moon till after the holidays.

(8) On July 20, 2069, people will say, “Neil who walked on what?”

In other words, we’d probably cope. If it were left to me I’d say go ahead, but there are a lot of scaremongers out there. A sampling of proposed fatal scenarios:

(1) Loss of the meteorite shield and resultant flaming death. Some say that if not for the moon, all those meteorites that made huge craters (150 miles and more in diameter) on the lunar surface would have flattened Nebraska instead. Like anybody would have noticed. My feeling is, while lunar shielding may have been important in the early days of the solar system, how many giant meteorites do you see crashing into the moon now? I want to know what the moon has done for me lately.

(2) End of life as we know it. In his book What If the Moon Didn’t Exist? Voyages to Earths That Might Have Been (1993), astronomer Neil Comins speculates that life would never have evolved from the primordial soup if not for the moon and accompanying tides. With weaker solar tides and thus a lesser distance between the littoral reach of high and low tides, there would have been fewer tidal pools, the petri dish for so many forms of life. As one commentator puts it, no amphibians = no land animals = no us. However, at the risk of appearing ungrateful, I have to point out that, evolutionarily speaking, we’re kinda past the lizard stage. The riposte to this is that even now tidal motion helps keep the oceans churned up, circulating nutrients and generally helping to promote life beneath the waves. No churning = no circulating nutrients = no life.

(3) Orbital instability. This has been the most controversial area of all. At first my reaction was, what orbital instability? Everybody knows that the radius of the earth’s orbit r = GM/v2, where G is the gravitational constant, M is the mass of the sun, and v is the earth’s orbital velocity. In other words, orbital radius is independent of planetary mass, so despite the loss of 1/81 of the combined terralunar bulk, orbitwise the earth would rock on. Various individuals claim, though, that earth’s orbit would become more elliptical, its axial tilt would become wobblier due to the influence of Jupiter, and who knows what else. If God had been subject to this kind of environmental impact stuff, the creation of the universe would still be in community hearings. I say let her blow. How bad could it be?

Cecil Adams

Send questions to Cecil via cecil@straightdope.com.