Astronomers are concerned about one of the stars in Orion's belt.

If you've ever gazed up at the sky on a clear night, you know the constellation Orion. It's visible around the world and recognizable even to people who aren't stargazers or astronomers. Right now, though, it's astronomers who are concerned about one of the star's in the constellation, Betegeuse, located on Orion's right shoulder.

Astronomers first noticed that the star was dimming back in August. Betelgeuse is a red giant and one of the ten brightest stars in the sky. By the beginning of December, though, it had dimmed so much that it's now not even among the twenty brightest stars, according to National Geographic. Scientists say it's not unusual for a star like Betelgeuse to dim, but it is unusual for it to dim so quickly. This could mean that the star will soon explode in a supernova.

This isn't something to worry about for us, since Betelgeuse is too far away for its explosion to affect us. Astronomers say it will take six million years for the shockwave to reach us and that the sun will protect whoever's still around then from any debris. Scientists think it's possible that the star will explode anytime in the next million years or that it's already exploded. It takes six hundred years for light from Betelgeuse to reach us, so if we see it explode now, that means it happened long ago.