Deep Impact

This is cool, and I am going to waste hours playing with this. Becky Ferreira reports that a blizzard was not the only thing we missed out on yesterday.

[A]n enormous space rock missed Earth by a narrow margin of 745,000 miles, or about three times the distance from the Earth to the Moon. With a diameter of 550 meters and a velocity of about 35,000 miles per hour, the asteroid, known as 2004 BL86, will be so bright in the evening sky that it will be visible through binoculars. Scientists don’t expect another object of this size to pass so closely to Earth until August 7, 2027.

But what if this asteroid had hit the Earth? Well, now you can play with Purdue University’s Impact Earth tool I linked to above.

Impact Earth allows users to input details about asteroids, comets, and other cosmic death traps, then crunches the numbers on the fallout. I gave the calculator the known details about asteroid 2004 BL86, including its diameter and velocity. I entered a hypothetical mid-range angle of 45 degrees, and specified that the asteroid hit sedimentary land, not water. Then, I asked it to tell me what the damage would be like one kilometer away from the impact site. After a dramatic animation of an asteroid hitting New England, Impact Earth gave me a rundown of the designer catastrophe.

Naturally, it wasn’t pretty. “The projectile begins to breakup at an altitude of 49,800 meters (16,3000 ft),” Impact Earth predicted. It would be fractured by the time it hit the ground, striking the surface at a velocity of about 7.95 miles per second. The energy released would be about 5,120 megatons, which is 100 times more powerful than the strongest nuclear bomb ever detonated. It would leave behind a crater with a diameter of 3.64 miles and a depth of 1.26 miles—similar dimensions to Alabama’s Wetumpka crater. But as the calculator noted under the “Global Damage” category, the impact would not be enough to disrupt the Earth on a global level by altering its orbit or its axial tilt.