What if the Earth had no Moon?

If the young Earth had not suffered the impact that resulted in the creation of the Moon, what would our planet be like? Is there any way to know? Are tidal forces still thought to be instrumental to evolution, and without moon tides would life have evolved?

I’m aware of the Asimov essay, but that was only about the effect on human culture.

Also, this might be more IMHO, we’ll see, but wondering if there’s any concrete science to form the basis of speculation.

Women’s periods might be timed differently. What effects that would have, wow, it is hard to even speculate.

One theory of the origin of life involves organic chemicals having the opportunity to react in relatively close contact in tidal pools.

If We Had No Moon: An essay by Bernard Foing

What if the Moon Didn’t Exist?: Voyages to Earths That Might Have Been, by Neil F. Comins

Well, the date of Easter would be a lot different, that’s for sure.

Werewolves wouldn’t exist.
Columbus wouldn’t have impressed the Native Americans by predicting a lunar eclipse.
Andy Williams would have nothing to sing about.

Also, The Master speaks.

In the book “Rare Earth”, the authors (Ward and Brownlee) argue that the presence of the moon acts as a stabilizing force on the earth’s axial tilt.

Complex life would be less likely to evolve if the axial tilt were erratic because the climate could change more rapidly than evolutionary mutations could keep up.

I don’t have the expertise to confirm or refute their arguments, but they made sense when I read them.

Actually, there’s no evidence the women’s menstrual cycles are lunar-based. Of all the mammals, only a very few have 29-day periods.

(Asimov had an essay on that, too. The only other mammal he identified as having a 29-day period was the platypus.)


We’d still have solar tides, sufficient to produce tide pools. Smaller ones, but they’d still be around.

Plus it’s not as if that “29” is carved in stone. It definitely doesn’t apply to all women, and there wouldn’t be so much fuss about the discusion of whether women living/working together synch sometimes or it’s just happenstance once in a blue moon if you could take it for granted that women will, indeed, be in synch. I’m not even sure if the 29 is an actual average for any specific population or just a number that someone plucked out of a mythical sleeve.

It’s 28, not 29. http://www.womenshealth.gov/publications/our-publications/fact-sheet/menstruation.html#b All the oral contraceptives I’ve ever seen come in packs of 28.

Either Discovery or TLC had a program called “If We Had No Moon” a few years ago.

Go from there.




Obligatory nit-pick:

Isaac Asimov imagined life on Venus too: The Weapon Too Dreadful to Use, 1939, short story.

Stubby Wiki article with synopsis:

TL;DR: The weapon casts a brain-disconnecting ray, capable of targeting narrow angle (a single individual) to wide-angle enough to target the entire Earth, that disconnects the brain from the body, leaving victims in a total and irreversible state of Locked In Syndrome. And, despite the misleading story title, the Venusians did use it in their battle for independence.

Full text of story.

Much smaller. Currently, solar tides are about half the size of lunar ones. When the Earth was young and life first came into being, the Moon was much closer to the Earth and lunar tides were something like 50 or 100 times larger than now. What effect, if any, that had on the origin of life is unknown, but that’s because we don’t know how life originated. We also don’t know exactly how close the Moon was to the Earth at that time, but that probably doesn’t make much difference. The tides were huge and a small change in the Earth-Moon difference would not change that significantly.

There’s some species that use the moon or its tides for various things. Off the top of my head, corals time their spawning to coincide with certain tides. I’m sure there’s others, but nothing comes to mind right now.

Related topic from The Master

If there was no moon someone on the Dope would be asking “What if the Earth had a moon?”.

The Apollo program would’ve never happened.

Neil Stephenson wrote Seven Eves, which speculates what happens to Earth when the Moon is mysteriously destroyed. Good read.

Well - I had believed that the tides were important in the movement of life from the oceans to the land. But this articlesupports the notion mentioned above that tides were critical in the development of life itself. However . . .

If the moon were not out there, we would have no romance. lol