A Near Miss and a Small Hit

Today was fairly momentous in terms of astronomical happenings.

We had the closest meteor-visitor in my lifetime, 2012 DA 14 that passed within 17,000 miles of Earth (the moon is about 220,000 miles from Earth), and a meteor smashed into Earth's atmosphere traveling at 33,000 mph, broke apart and wound up injuring over 500 people in Russia (but killing 0).

Photo courtesy NASA

The two events were reported as unrelated on account of the Russian meteor strike being on a different trajectory than 2012 DA 14, though it is a very strange coincidence.

Unfortunately, I was working when 2012 DA 14 passed by, so I missed the show, but below is a series of shots by NASA showing our rocky visitor passing by.

Courtesy NASA

What if 2012 DA 14 had struck Earth?
I read earlier today that DA 14 had about the same mass as the meteor that caused the Tunguska air-blast of 1908 that leveled an area with a 50 mile radius—about equal to a hydrogen bomb. So it would have been bad news for anyone underneath it, but DA 14 was not even close to being on the scale of the meteor that killed the dinosaurs, or even Apophis—the meteor predicted to have a small chance of striking Earth in 2036 which is massive enough to cause global temperatures to fall and block out some of the sun's light. (And yes, Apophis is named after the Stargate SG-1 character, its discoverers are SG-1 fans).

Fortunately, we have 20 years to prepare for Apophis, and its orbit is well known. Some scientists predict that if it is determined to be a real threat to Earth, we could do something about it in time—so don't worry just yet (and if you're in the USA, tell Congress to fund NASA!)