Constable: What's big, fast, hazardous and should swing by Earth before Thanksgiving?
Burt Constable
Worried about the impeachment battle, the pending presidential election, the Chicago Bears offense, the seating arrangement for Thanksgiving? An asteroid twice the size of the Eiffel Tower and zipping toward Earth at 18,000 mph could add to your worries. Or, theoretically, make them all go away.
According to the Center for Near-Earth Object Studies, or CNEOS, at NASA, the folks who recently brought you the 50th anniversary of the moon landing, a 2,034-foot-wide asteroid dubbed 481394 is "a potentially hazardous asteroid."
Oh, and the predicted "near-collision" could happen as soon as Nov. 21, about the time astronomer Mark Hammergren of the Adler Planetarium will be giving an address at the Illinois Institute of Technology. But he's not worried this asteroid will cut short his talk.
"It's not scary at all," Hammergren, a member of CNEOS, says of the asteroid. "We know this one very well. It's large, so it's easy to see."
Scientists have been tracking it since 2006 and calculate that it will miss the Earth by 27 million miles, although Hammergren admits the margin of error is plus or minus 15 miles. That's the equivalent of monitoring a truck on a highway 30 miles away and knowing its exact location within an inch, Hammergren says.
Meanwhile, Earth does get hit by 100 tons of space stuff (mostly dust) every day. A meteor about 3 feet across lit up the sky west of St. Louis earlier this week, but it caused no damage, Hammergren says. "They are moving so fast, when they hit the Earth's atmosphere, it's like hitting a brick wall."
In 2013, the largest meteor in a century entered Earth's atmosphere with a diameter of about 50 feet. The biggest chunk that made it to the surface in Russia probably was a 3-foot piece that fell harmlessly into a lake, the astronomer says.
"None of the pieces did damage, but the sonic boom broke thousands of windows" and left some people injured, Hammergren adds.
For comparison, the asteroid believed to have wiped out the dinosaurs about 65 million years ago was roughly the size of Mount Everest, Hammergren says.
The astronomer, who helped track asteroids during a research project at the Apache Point Observatory in New Mexico, says scientists know about thousands of potentially hazardous asteroids, which are greater than 300 feet across and on path to come within 4.6 million miles of our planet.
"And not a single one is on a collision course with the Earth," Hammergren says.
If Earth were a basketball and the moon were a tennis ball, a 328-foot-wide asteroid flying between the two would be smaller than a grain of sand jetting through an area as wide as a professional soccer goal, according to NASA.
Still, NASA is working on a plan to change the orbit of any asteroid on a collision course. In 2021, NASA is slated to launch a Double-Asteroid Redirection Test, or DART, in which a Smart Car-sized DART spacecraft will slam into the football-stadium-sized moon of a larger asteroid to see how the collision changes the asteroid's orbit.
Even an asteroid the size of the one that spelled doom for the dinosaurs, while catastrophic, probably wouldn't lead to the extinction of humans, Hammergren says. Massive ash-spewing volcanoes are more likely than asteroids to cause issues, he says. We are more prepared for asteroids.
"This is the most unsung victory of NASA," Hammergren says. "We have found all the large asteroids that could cause a mass extinction. Global destruction from an asteroid, we have eliminated that threat for a least 1,000 years. You're not going the way of the dinosaurs. And that's a great Thanksgiving story."