Look to the east over the horizon tonight, and you could get a glimpse of the last major astronomical event of the year.
The Geminid Meteor Shower continues to bombard Earth’s atmosphere, and the best times to see the flashing streaks of light are expected to be tonight and early Friday morning, Decatur astronomer Loren Ball said.
“It’s going to be cold, and you’re probably going to have to be up at 3 or 4 in the morning,” Ball said.
Ball is called an “asteroid hunter” by other astronomers. He has discovered more than 100 new asteroids from an observatory built into the roof of his Emerald Lane home.
He is under contract with NASA through the University of Alabama in Huntsville to speak about space science to school groups and other organizations.
An asteroid becomes a meteor when it enters earth’s atmosphere. Ball said about 20 meteors per hour will enter Earth’s atmosphere during peak hours. The meteors have been shooting for a couple of days already and could continue for another week.
“They’re hard to predict,” Ball said. “Nobody knows exactly when they start and stop.”
The meteors will radiate from the Gemeni constellation, hence the name “Geminid.” Ball said knowing the origin of meteor showers is rare. The Geminids’ parent, a space rock called 3200 Phaethon, was discovered by NASA in 1983. Scientists theorize that Earth’s orbit around the sun is creeping ever closer to 3200 Phaethon’s debris field, meaning the showers could become more intense in future years.
Ball said Earth collects 15,000 tons of matter per year from meteorites.
“A lot of people think the meteors are a pretty good size, at least as big as a Buick,” he said. “But in reality, they are almost always the size of a grain of sand.”
What they lack in size, they make up in speed. The meteors strike the atmosphere at about 20 miles per second, and the sheer amount of kinetic energy released upon impact makes the light show happen.
“That’s 50 times the speed of a rifle bullet,” Ball said.
Celestial events over the last week, such as two asteroids passing close to earth, have been difficult to view because of the moon. But tonight marks the beginning of a new moon, meaning the Geminid meteors should be easier to see. Skywatchers are advised to leave cities to see the spectacle because the lights will cloud the view of the sky.
NASA will broadcast a live feed at www.nasa.gov tonight, streamed from a light-activated camera mounted at Marshall Space Flight Center in Huntsville.