This is the most powerful object in the Universe. The biggest spinning magnet to ever exist.

It’s the cosmic equivalent of a great white shark. But it wouldn’t eat you. It would just turn all your atoms to dust…

If you thought neutron stars were big and scary, well, you haven’t heard of their more powerful stellar cousins yet. Like neutron stars, magnetars are leftovers from supernova explosions.

They’re just packed with a lot more matter. Their density is so high that a single teaspoon of a magnetar could weigh in at a billion tons. They are also the most magnetic stars we know about.

We use a unit called a Gauss to measure the strength of a magnetic field. Earth’s magnetic field is only about 0.6 gauss. A refrigerator magnet is 10 Gauss. The most powerful magnet on Earth right now is about 410,000 Gauss.

A magnetic field of a magnetar can be as strong as one quadrillion gauss. That’s a one with 15 zeros behind it.
How long would it take a stellar monster like that to rip our planet apart?

It wouldn’t be the worst thing in the world if a magnetar was sitting quietly in our galactic neighborhood minding its own business. But if it decided to stop minding its own business, there are two ways a magnetar could end all life on Earth together with the planet itself.

It could get too close to the planet. You’d start to feel its presence when it was about halfway between the Moon and the Earth. At that distance, a magnetar would erase the information off all of your credit cards’ magnetic strips.

Whatever you do, try not to get any closer than 1,000 km (620 mi) from a cosmic invader. Because if you did, your atoms would get stretched out of shape. Your bioelectric field would get scrambled, disintegrating your molecular structure. And your body would just disappear.

Alternatively, a magnetar could destroy us from much, much further away. As if being the biggest spinning magnets in the Universe isn’t enough, magnetars can also be affected by something called starquakes.

Starquakes happen when a star’s crust cracks, letting massive amounts of radiation out into space. This blast of radiation could compress the Earth’s magnetic field and partially ionize Earth’s atmosphere even from 50,000 light years away.

We know this because we’ve already come a little too close on at least one occasion. In 2004, gamma radiation from a magnetar reached our planet from outside of our Milky Way galaxy. In just one-fifth of a second, it released more energy than our Sun has released over the last 250,000 years.

Move that magnetar and its starquake up to 10 thousand light-years away, and things would get much worse. First, it would destroy our ozone layer. Then, it would wipe clean most of the planet’s surface, along with all life as we know it.

The truly scary part of it is that we wouldn’t even know the magnetar was heading toward us. It would be a “blink and you’re gone” scenario.

I won’t lie to you. There are magnetars close enough that if one had a violent starquake right now, we’d all get wiped out very fast.

When scientists began their search for these interstellar monsters 40 years ago, they didn’t realize how many of them exist out there. You might find some comfort in the fact that most magnetars don’t make it much past their 10,000 birthday.

Their short lifespan ends with them becoming neutron stars – still dense and still magnetic, but not nearly as dangerous as a magnetar.

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