Asteroid 99942 Apophis will come with 9.2 million miles of the Earth at 7:09am MST. Normally this would not be an observation of note, but astronomers will be paying close attention. Apophis has the potential of hitting the Earth. On April 13, 2029 (a Friday), the asteroid will pass inside the orbit of geosynchronous communication satellites which are 22,500 miles above the Earth. That’s close enough to significantly affect the asteroid’s orbit. It will also be bright enough to be seen by millions of people. Not bad for an object 855 ft. in diameter and black as coal.
Just how the asteroid’s orbit will be affected in 2029 is not known. There is a 1 in 250,000 probability that asteroid could hit the Earth on its return trip on April 13, 2036. The possibility is remote, but cannot be ignored. If it does hit the Earth it would hit with the force of at least 34,000 Hiroshima bombs.
Apophis is a reminder that we live in a celestial shooting gallery. We have been hit before and we will likely be hit again. The last major hit was in Tunguska, Siberia in 1908. That 10 megaton explosion destroyed 80,000,000 trees over an 830 square mile area. Apophis would be fifty times more powerful.
The asteroid will be far too dim in 2013 to be seen without a good sized telescope. If you want to see Apophis you can go here on January 9, 2013 at 6pm MST and on January 21 at 3PM MST for a live observation session with commentary presented by The Virtual Telescope Project.
Wishing you clear skies