The Moonquake Mystery: How the Moon Is More Active Than You Think

It’s kind of funny how, for most of our lives, the Moon gets treated like this calm, predictable rock. It’s quiet, it’s steady, it’s always there. But the more you learn about it, the more you realize: the Moon has drama. Because, despite how peaceful it looks, the Moonquakes. And not just tiny, harmless tremors — we’re talking long, ringing, drawn-out vibrations. The Moon is way more alive on the inside than it lets on, and once you uncover the details, you never look at it in the same way again.

The Moon “Rings Like a Bell”

One of my favorite Moon facts of all time is how the Apollo astronauts placed seismometers on the surface, and when they later intentionally crashed parts of the mission hardware back onto the Moon, the vibrations didn’t fade in a few seconds like an earthquake would. The Moon rang, literally rang, for almost an hour.

And that tells you a lot about what the Moon is made of. Earth has water, molten rock, tectonic plates, and a lot of squishy, flexible layers that absorb seismic energy. The Moon, meanwhile, is dry, brittle, and rigid. It’s basically one giant echo chamber. When it shakes, the energy has nowhere to go. So it lingers. And that’s where this whole moonquake mystery really begins.

The Four Types of Moonquakes (And Why They’re So Weird)

To understand how alive the Moon actually is, you have to understand that not all moonquakes are created equal. Apollo data revealed four distinct types — each caused by something completely different. And honestly, each one adds another layer to how unexpectedly chaotic the Moon can be.

Deep Moonquakes

Deep moonquakes happen 600 miles beneath the surface — deeper than most earthquakes on Earth. And what’s spooky is that these quakes repeat on a schedule. Almost like clockwork. Every 27 days, when the Moon reaches certain parts of its orbit, deep quakes occur in the same spots. Why? Because Earth is literally tugging on the Moon so hard that it’s pulling its insides around.

Thermal Moonquakes

A lunar “day” lasts 29 Earth days, which means when the Sun finally rises after two weeks of pitch-black cold, the temperature jumps by hundreds of degrees. All that frozen rock suddenly expands, shifts, cracks — and boom, you get a thermal moonquake. Imagine every building in your town snapping and popping at sunrise because it finally warmed up. That’s the Moon.

Impact Moonquakes

Since the Moon has zero atmosphere, even tiny meteoroids strike the surface at ridiculous speeds. Honestly, the Moon is basically a punching bag for space debris. These impacts send intense shockwaves through the crust. Most of the craters we see with our naked eye today were formed millions or billions of years ago — but the impacts haven’t stopped. Not even close.

Shallow Moonquakes

These are the big ones. Shallow moonquakes occur only 20–30 miles below the surface and can reach a magnitude of 5.5, which is strong enough to destroy structures on Earth. Worse, shallow quakes last forever by Earth standards. Some continued shaking for 10 minutes, and others kept vibrating for longer than that. That’s the kind of seismic event that could threaten lunar bases or habitats if we ever really settle there.