Apocalyptic video shows what would happen if a needle hit planet Earth at the speed of light

An apocalyptic video shows what could happen if the Earth was struck by an object from outer space.

But the object isn't quite what you might think. It's not a kilometres-wide asteroid, nor is it a comet or a meteor.

No, this is a most a humble needle, like what you might use to sew on a button. Okay, it might sound laughable at first but what if I told you that in this theoretical scenario the needle was travelling at the speed of light?

Now things are getting a bit more serious.

Surely the Earth would still be okay? It might do something, but surely something as small as a little needle wouldn't do that much damage?

Well, there are a couple of ways this could play out, and let's just say that one option is definitely preferable to the other. A video from Ridddle on YouTube takes a look at the options.

In the tradition of good news and bad news, let's start with the worst case scenario if a needle were to strike the Earth at this speed.

YouTube / Riddle

In the worst case scenario, the energy dissipated by the needle would cause an apocalyptic event on the Earth. It would create a big hole in the Earth's crust causing a huge outpouring of the Earth's mantle to be thrown into space.

This means that life as we know it is extinct due to the enormous heat released by the impact.

But wait, it gets even worse.

It could even be that the energy released by the impact is so great that the Earth literally disintegrates under the sheer force of energy. Yes that's right, the entire Earth is just blinked out of existence by a needle.

Or not blinked, because it would be faster than that.

So that's the worst case scenario. At least it would happen so quickly that no one would even know about it.

But what about the good option?

Well, in this case - as the needle is sharp and travelling so quickly - there's a chance that the energy would not be released in time to actually significantly impact the Earth.

In this scenario, the needle would simply go into the Earth and then come out of the other side. Not only that, but it would happen so quickly that no-one would even notice.

Unless you happened to standing where it came out in which case, bad luck.

This is of course and entirely theoretical scenario, but it goes to show the immense amount of energy that something travelling at the speed of light has - even if it's a relatively small object like a needle.