When we think of the moon, we usually picture a calm, silent ball of rock just floating peacefully in space. But guess what? That calm little rock actually shakes. Yep, the moon has earthquakes, and they’re called… moonquakes. (10/10 for naming creativity, NASA.)
So, what exactly is a moonquake?
Moonquakes are tremors or vibrations that happen on the surface or deep inside the moon. They’re similar to earthquakes here on Earth, but they occur in a place with no oceans, no tectonic plates, and no humans jumping up and down.
Scientists first discovered moonquakes thanks to the Apollo missions in the 1960s and ’70s. Astronauts left behind seismic equipment (kind of like spacey earthquake detectors), and these gadgets picked up rumblings on the moon’s surface. That’s how we learned: even space rocks get the shakes.
What causes the moon to tremble?
Good question! There are a few different types of moonquakes.
| Type of moonquake | What causes it | Fun fact | Stats |
|---|---|---|---|
| Tidal | Earth’s gravity is pulling on the moon | Yes, we’re literally shaking the moon! 🌍➡🌕 | Deep; regular; predictable |
| Thermal | Rapid temperature changes on the surface | Like the moon going from sauna to freezer 🔥❄️ | Near surface; small; daily-ish |
| Impact / Meteoritic | Meteoroids hitting the moon | Space rocks don’t knock before visiting ☄️ | Surface-level; short-lived |
| Deep (mystery!) | Unknown, possibly internal stress | Still keeping scientists up at night 🧠🌌 | ~700 km deep; low magnitude; can last hours |
| Shallow | Crust shifts or unknown surface stress | The moon’s dramatic side – big and long quakes 😱 | Up to M5.5; can last 10+ minutes |
Officially, scientists categorize moonquakes into four types: deep, shallow, thermal, and impact. In this table, tidal moonquakes are listed separately to highlight the role Earth’s gravity plays, though they’re technically considered a trigger for deep moonquakes rather than their own category. I just thought they deserved a little spotlight.
And here’s the kicker: moonquakes can last for hours. That’s way longer than earthquakes on Earth, which usually stop after seconds or minutes. Why? Because the moon is bone dry and doesn’t have a soft, squishy mantle like Earth does to absorb the vibrations. Once it starts shaking, there’s no gentle “shhh” to calm it down.
Why does this matter?
With space agencies talking about building moon bases or even little moon villages (how cute would that be?), moonquakes are no small deal. Structures would need to handle long-lasting vibrations in a low-gravity, no-atmosphere environment. Not your average construction project.
Final thought: The moon has no chill
So next time you look up at that glowing orb in the sky, remember – it might look peaceful, but it’s literally quaking on the inside.
Space: not as quiet as it seems.
Curious to dig deeper? Check out these reliable sources for more info on moonquake categories and what causes them:
- ScienceDirect: Overview of deep, shallow, and impact moonquakes
- Museum of the Earth: Describes the four main moonquake types and their stats
- NASA: Apollo 11 Seismic Experiment explains how seismometers first detected moonquakes
- Science.org: Discovery of thousands of moonquakes using Apollo data.