Swapna Krishna

Jan 2nd 2023

What Are Spacequakes, and How Do They Happen?


You’ve heard of earthquakes. You may have even heard of Marsquakes. But have you heard of earthquakes in space, or spacequakes?

Earth experiences a sort of quake in its magnetic field. It’s part of the complex space weather the planet endures on a daily basis (very different than atmospheric weather — more on that later). Let’s explore what spacequakes are, why they happen and what effect they have on our planet.

Earthquakes, Marsquakes, Starquakes — Oh My!

Before talking about the ones that occur in space, it’s useful to understand what causes earthquakes in the first place. Earthquakes happen when the planet’s tectonic plates, which are constantly moving and shifting, get stuck. Stress builds up between the plates, and when they are finally able to move again, a tremendous amount of energy known as an earthquake is released.

The moon and Mars both have quakes on their surfaces, too, just like Earth, but they are distinct from one another. Earthquakes travel in a direct way through the planet while moonquakes are more scattered. Marsquakes fall in between these two. And that’s not all — there are all kinds of quakes around our solar system.

Starquakes occur in a specific type of dense neutron star, which is the remnant of a massive star’s core after it’s collapsed, called a magnetar. A magnetar is a neutron star with a magnetic field so strong that it actually warps the outer layer of the star, a hard crust that forms over a fluid core. When this warping occurs, it’s called a starquake.

Asteroids have quakes, too. Over the millions and billions of years that asteroids move through space, their surface turns a dark red color thanks to exposure to cosmic rays and radiation. But some don’t, and scientists believe this is due to close flybys of planets that cause seismic events on asteroids. As they’re twisted and rocked by the gravity of other planets, that red muck is cleaned off thanks to seismic asteroidquakes.

How Are Quakes in Space Different?

Obviously, spacequakes are different than earthquakes and quakes of other planetary bodies because there aren’t shifting tectonic plates to think about. But there are strong magnetic forces that make up spacequakes. These earthquakes in space are still considered temblors or tremors, but instead of being on land, they’re located inside Earth’s magnetic field.

Earth’s magnetosphere is one of the reasons life can exist on this planet. We have a strong magnetic field compared to our fellow inner rocky planets. This protects us from space radiation and our atmosphere from erosion, among other things. But despite its protective nature, our magnetosphere isn’t a calm and tranquil place. Interaction between our magnetic field and solar wind is what creates space weather — and earthquakes in space.

Earth’s magnetic field is extended out like the tail of a comet thanks to solar wind. When it gets overstretched, it ends up snapping back like a rubber band. That’s when spacequakes, which were first detected in 2010 by the THEMIS spacecraft, occur. Solar wind plasma (also called ionized gas) that’s trapped in the magnetic tail is released and races toward Earth. It gets caught in Earth’s geomagnetic field, but the impact sets off a chain of events in which the trapped plasma actually bounces off the magnetic field over and over again.

When this happens, it creates “space twisters,” or vortices, high above Earth’s equator. They’re visible from Earth through auroras, where they can create ripples. Spacequakes are so strong that their energy is equivalent to a magnitude 5 or 6 earthquake, and while they occur in space, the reverberations can reach Earth’s surface. These strong magnetic events can also instigate spikes in electricity that can affect the power grid.

While these earthquakes in space may have electromagnetic effects that can reach Earth’s surface, they generally don’t cause permanent damage of any kind. But researchers are still delving into the potential implications of these natural phenomena to understand their short- and long-term effects on the planet.

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