Q: When is it?

A: The meteor shower that is expected Friday has never been seen by humans, and astronomers say it could be spectacular. They also say it could be a total bust.

Q: What is it?

A: The shower will occur when Earth passes through the dust trail left mostly in the 1800s by a comet identified as 209P/LINEAR. When the particles hit Earth’s atmosphere, they will vaporize and leave bright trails.

Q: Why do scientists say it may be a bust?

A: Because it hasn’t happened before, astronomers aren’t sure what to expect. If the comet left a lot of debris, we could see hundreds of meteors per hour. If it didn’t leave much, we won’t see much.

Q: Where do I look?

A: Look up. Meteors will originate near the constellation Camelopardalis (the giraffe), which is near the North Star, but they could show up all over the sky. People in North America will have the best view.

Q: Why has no one seen it before?

A: Jupiter’s gravity recently pulled the comet’s debris into Earth’s orbit for the first time. The comet itself is so small and unobtrusive that astronomers didn’t see it until 2004, when a new high-tech telescope detected it while searching the sky for asteroids.

Q: I don’t want to get up at 2 a.m.

A: Astronomers expect the show to begin about 10:30 p.m. and peak between 2 and 4 a.m. Saturday, so try looking early.

Q: Will the particles hit us?

A: According to NASA, the particles are the size of a sand grain to begin with and will vaporize long before they reach Earth.

Q: What if I blink?

A: As meteors go, these are not in a hurry. They are expected to be bright and to travel at about 12 miles per second — pedestrian when compared with Perseid showers and downright slothlike when compared with Leonid showers.