Astronomers at NASA are calling it a “close shave.” Don Yeomans and his associate Paul Chodas, working with the NASA Near Earth Object Program Office on February 1 reported that an asteroid, Asteroid 2012 DA14, will pass within the orbits of some of our geosynchronous satellites but will not impact our planet. Since the asteroid has an orbit that the NASA program describes as similiar to Earths, they have been able to monitor the object, and assure us we are in no danger. Yeomans says Earth’s neighborhood is littered with asteroids of all shapes and sizes, from tiny fragments to mountainous rocks. Some come from the asteroid belt, between Mars and Jupiter; some are all that remains of ancient comets.
2012DA14 is made of stone, not metal or ice. It will be closest on February 15, 2013, at about 2:24 P.M. Eastern Time. The hurling rock is expected to come no closer to our planet than 17,200 miles. While some of our man made satellites are within that range, the majority of satellites and the International Space Station are at a distance of 22,200 miles. The path of 2012DA14 will bring it to about 1/13th of the distance to the moon.
Yeomans says that the impact of a 50 meter asteroid — described by some observers as “gymnasium size,” by others as “half the size of a football field” is “by no means cataclysmic; unless you happen to be under it!” he adds. Astronomers say that in the hypothetical situation of 2012DA14 entering our atmosphere, it would release 2.4 megatons of energy. “Not a world killer”; if it were to strike the ocean, or Antarctica, the impact might even be harmless.
A similar sized object, but made of metal, formed the mile wide “Meteor Crater” in Arizona. That was 50,000 years ago. And in 1908 a rock of about that size exploded over Siberia, where that “Tunguska Event” leveled hundreds of square miles of forest. Amateur ski-watchers will find this coming asteroid hard to see; it will be moving south to north at 17,400 mph.
2012DA14 was discovered by astronomers at the La Sagra Sky Survey program in the South of Spain, who reported it the Minor Planet Center. At that time the passage was 7 times the distance to the moon. They calculated the orbit to be at about 368 days. It passes, they explained, every year. This passage, in 2013 will be the closest yet, giving astronomers at NASA’s Goldstone Radar in the Mojave Desert an opportunity to study the object for factors such as size, spin, and reflectivity. The pass in February will alter the orbital period to about 317 days, and any future close approaches will follow a different pattern. The asteroid will not make another close approach for at least 3 decades.
Yeomans mentions that “The odds of an impact with a satellite are extremely remote; nothing orbits where DA14 will pass.”