45. On February 15, 2013, Asteroid 2012 DA, passed within 17200 miles [mi] of the surface of the Earth at a relative speed of 78 kilometers per second [km/s]. This is considerably closer than the orbit of geosynchronous satellites (26,200 miles). This is the closest recorded approach of an object this large. The asteroid 2012 DA,, was estimated to have a diameter of 30 meters [m] and a specif- ic gravity of 3. If 2012 DA4 had hit the Earth, what is the total amount of energy that would have been released (i.e., what was the kinetic energy of the asteroid)? Express your answer in megatons [Mton]. One megaton is the energy released by one million metric tons of TNT explosive. A metric ton equals 1000 kilograms [kgl, and the explosive energy of TNT is 4184 joules per gram [Jel