This Sunday night, December 13, we’ll see the year’s finest meteor shower. These are the Geminids and they deliver a meteor a minute.
The good news continues: This year, the Moon will be thin and harmless, so the spectacle won’t be spoiled by a bright, milky, background sky. And this shower, unlike the more famous August Perseids and the hit-or-miss November Leonids, doesn’t require you to set an alarm. These meteors aren’t post-midnight streakers; they’re nice starting as early as 9 p.m.
Geminids are much slower than the other major showers because they don’t strike us head-on. They come at Earth sideways. They lope along at half the speed of the Perseids and Leonids, and it shows. Instead of sharp, brief zaps across the sky, we get leisurely ‘falling stars’.
There are other oddities, too. All other major meteor showers have been observed for centuries or millennia. But the Geminids were unseen as recently as the mid-1800s.
Geminids are also the most mysterious meteors. All other showers are debris from comets, skimpy stuff, chunks of ice. Strangely, Geminid meteors are twice as dense. What could they be?
The source of these strange fireworks was unknown until 1983, when NASA’s infrared-detecting satellite found a small body moving in exactly the same path as the meteoroid swarm. Named Phaethon (say FAY-uh-thon) it has an oval orbit that carries it far within the orbit of Mercury and then out past Mars into the asteroid belt. Since Phaethon does not develop a cometlike tail nor shed material when approaching the sun, it was assumed to be an asteroid, a rocky body.
Except asteroids don’t disintegrate to produce meteor showers: How strange! So Phaethon seems to be an odd, unique, has-been comet. Either way, the mystery material puts on quite a show.
Try to get away from lights, to a place with an open expanse of sky. Bring a folding chair. In the middle of December, lingering outdoors after midnight is odd behavior, like mixing tuna fish with marshmallows the way my sister Jane does. But if you keep your eyes glued upward, and if it’s clear, you WILL see meteors, guaranteed.