Asteroid 2012 DA14 will come within 17,200 miles of the Earth Friday afternoon around 1:25 pm MST. There is no risk the 165 foot diameter asteroid will collide with the Earth. While 17,200 miles is a long way, astronomically it’s a record setting close approach. Consider this: If your head was the Earth and the asteroid a bullet, the bullet would miss your head by 16 inches.
According to NASA, asteroids this size come around every 40 years or so. Expect one to hit the Earth once in a 1200 year period. That’s a 1 in 30 chance for objects this size. If it were to hit the Earth the explosion would be in the 2.5 megaton range. That’s around 150 times the power of the atomic bomb dropped on Hiroshima. NASA compares it to such events as the mile-wide Barringer Meteor Crater in Arizona and the Tunguska Siberia event in 1908.
Viewing the asteroid will be difficult. Our friends in India will get the best chance to see the fast moving asteroid in binoculars. The dim asteroid will be difficult to locate and once located, hard to track. For them the asteroid will move two full moon diameters every minute. Here in the Denver metro area, the asteroid will be moving slower but will be 200 times dimmer. It will take a moderated-sized telescope pointed in just the right place to see it.
If you want to see what part of the sky the asteroid will be in. It will pass below Polaris, the North Star, between 9:00 pm and midnight MDT. To find Polaris look directly north 40 degrees above the horizon. Polaris, not particularly bright, is the most visible star in the area.
Wishing you clear skies