You may have seen meteor showers and wondered what they are. Well, most are actually the icy tails of comets.

As comets travel, they shed particles of dust and ice, then pull them behind in their wake to form a long tail. Each year, Earth’s orbital path passes through the tails of several comets that also orbit within our solar system.

When that happens, the particles burn up in our atmosphere. We see them as shooting stars.

There’s a particularly bright meteor shower that appears in the sky each December near the constellation Gemini—and is therefore called the Geminids.

These aren’t a comet tail, but instead the dust plume from a four-mile-wide rocky asteroid called 3200 Phaethon.

It also orbits the sun, at times traveling near enough that its surface gets superheated, causing it to spit off mineral dust, which it then pulls behind it like a comet tail.

You can see the Geminid meteor shower from around December 7 through 14, with the last two nights being the most spectacular.

For best viewing, you’ll need to be up around two in the morning. Find a place away from the city lights. Then find Gemini in the sky. Allow your eyes to adjust to the darkness, then get ready for the show.

Geminid meteor showers can produce hundreds of shooting stars, some multicolored. If you’ve got a friend with you, let them know they’re actually looking at asteroid dust—and that they can find out more at EarthDate.org.