ANCHORAGE - An asteroid is headed for earth! …But astronomers say there's no danger the space rock will hit us.
Asteroid 2012 DA4 is roughly the size of a football field. It’ll approach earth along a south-to-north trajectory, and come within 17,500 miles of the earth’s surface.
It'll be visible in Alaska around 10:25 tomorrow morning, but you won't be able to see it with the naked eye—or even binoculars. UAA Physics and Astronomy professor Dr. Andy Puckett said you'll need a telescope with a diameter of at least nine inches if you want to catch a glimpse of the speedy celestial object.
What’s unique about this asteroid, Puckett said, is how close it will come to earth: well inside the moon’s orbit and even inside the orbit of most weather and communications satellites. But he stressed that there’s no need for worry.
“They're very very certain of the orbit, they know its not going to hit the earth,” he said. But coming just between the earth and it’s artificial satellites, which means “it's just going to thread that needle.”
“This distance from the surface of the earth that its going to pass is about two earth diameters away,” Puckett said. “So picture grabbing two spare earths that you have lying around, and putting them next to each other.” As a point of reference, Puckett said the moon is usually about 30 earth-diameters away.
That’s the distance the asteroid will travel this year, but as it orbits the sun in a roughly earth-like orbit, Puckett said it will be back… just not any time soon.
“It's our neighbor, and it's going to keep coming back relatively close, but I think, the next worrisome close approach isn't until the 2040s.”
The UAA Planetarium hosts a talk every Friday about the stars, and Puckett said he’ll be talking about the asteroid tomorrow night at 6:30 p.m.