What would happen if there was no moon? It’s a complicated question with some surprising answers. If Earth had no moon because it just disappeared, things actually wouldn’t change a great deal right away. The tides would change, the night sky would be darker, and a whole lot of animals would be seriously confused. But if we had no moon, humanity would still survive quite nicely for a long, long time before feeling any significant impact.
But what if there was no moon because of a moon explosion? What if Earth had no moon because Earth blew it up? Both hypothetical scenarios yield some fascinating results – one is just a whole lot messier than the other. Read on to learn what would really happen if there was no moon.
The Tides Would Be Tiny
Since the tides would follow the sun instead of the moon in a moon-free world, they would also be significantly smaller. Why? The moon, while a lot smaller than the sun, is much closer to the Earth, exerting more of a gravitational “pull.” So sun-only tides would only be about 40% as large as moon-and-sun tides. This would also make tide patterns a lot simpler.
The Earth Might ‘Wobble Wildly’
It would take millions of years for this to even matter, but removing the moon from the night sky could make the Earth “wobble wildly” like Mars, according to Seeker. The moon currently acts as a shock absorber of sorts, keeping the current low-level wobbling caused by the sun’s gravitational pull under control. Remove the moon and the tilt of the Earth’s axis could change drastically over many millions of years, possibly making the seasons too extreme for life to survive (though some research suggests otherwise). The wobbling of Mars, for example, causes long-term climate change cycles on the Red Planet.
The Night Sky Would Be Much, Much Darker
No moon means no moonlight, which means a much darker night sky. There would be nothing left in the night sky that could even compete with the moon. Venus, for example, is the next brightest celestial object, but it’s only 1/14,000th as bright as the full moon. We would especially miss full moon nights, which are 12 times brighter than when the moon is in its first or last quarter.
Tides Would Follow the Sun
Fishermen of the world, rejoice! Getting rid of the moon would mean high tides around nooneverywhere on the planet, every day. The moon’s mass would no longer pull, gravitationally, on the Earth, meaning the tides would follow the sun instead. (Also: no need for complicated tide tablesanymore.)
The Earth Would Spin Faster
Thanks to a lack of so-called “tidal friction,” the Earth would spin faster if the moon disappeared, but not by much. The spin would increase the length of our days by just a few microseconds per year. But if we never had a moon in the first place, hypothetically speaking, the Earth spinning faster over millions of years would eventually leave us with days that are only about six hours long. Other side effects would include faster winds and stronger storms.
There Would Be No Lunar or Solar Eclipses
This seems obvious enough, but it’s easy to take for granted: no moon means no lunar or solar eclipses. This means you’d have to rely on Venus to get your eclipse fix. It’s the next closest thing we would have, sans moon. The only trouble is a Venus eclipse (also called – ooh la la! – a “Transit of Venus”) won’t happen again until 2117. The last (pictured) one took place in June 2012.
There Would Be More Bug-Eyed Creatures
Darker night skies would lead to the evolution of more “bug-eyed” creatures, according to astronomer Neil F. Comins. Comins says nocturnal animals would have to “develop bigger or more sensitive eyes to help them navigate, forage and spawn at night” under a moonless sky. As Comins notes, moonlight is simply “scattered sunlight at night,” and without that light, animals would be forced to adapt. If there was never a moon in the first place, well… who knows what kind of “night vision”-enabled creatures may have evolved?
It Would Change the Altitude of the Oceans
Without the moon’s gravitational pull, the middle of the globe would be a lot less flabby. The “bulge” of ocean water near the equator would disperse to the poles. This would mean that the overall altitude of the world’s oceans would change. This change in the “mixing of the deep ocean” could affect the climate in many ways (see, for example, the Pacific Ocean’s El Niño phenomenon).
It Would Be Harder to Learn About Asteroids
Scientists say that the moon is “the best place to study and harvest asteroids” and it “represents a planetary Rosetta Stone of the asteroid bombardment record.” Without the “asteroid magnet” moon, we would lose out on a relatively close laboratory for studying space rocks. That’s not to say, however, that the moon is in any way protecting us from asteroids (it’s too small). Our own atmosphere does a much better job of that.
Mercury Could Get Ejected from Its Orbit
Remember in 2006 when everyone got mad that Pluto wasn’t a real planet anymore? Well, without the moon, Mercury may lose its planetary status, too, but not just because of semantics. The “Earth-Moon team,” as the Straight Dope points out, may be what’s keeping Mercury in its place. Without our gravitational influence, Mercury could face a “high-stakes run-in with Venus” that would eject it from its orbit and send it “bonking into who knows what along the way.”
Reproduction Would Change for Many Aquatic Animals
Getting rid of the moon would mess up the reproductive rhythm of many aquatic animals that rely on the moon’s light and impact on the tides. Studies show that a wide variety of creatures would have to change their behavior to adapt to a moonless world. The grunion fish, for example, famously spawn only a few days after a full or new moon. Scientists link this behavior to the tidal cycle, which would be drastically different without the moon.
Menstrual Cycles Would Stay the Same
Contrary to a popular belief, there’s no connection to the lunar cycle and menstrual cycles. It’s pure coincidence that they’re about the same length. There’s no proof, in fact, that the moon has any impact on childbirth or insanity, either. The widespread belief in “lunacy” being connected to the moon has many reasonable explanations, including the theory that bright, full moons, before gas lighting and electricity, kept people awake longer. Sleep deprivation is known to cause mania (even just one night!), so over centuries, a correlation was made, the theory goes, between full moons and manic behavior.