This coming Friday, February 15, 2013, we will have a flyby of asteroid 2012 DA14. This asteroid is about 45 meters (150 feet) in diameter and is most notable in that it will pass within the orbits of our geosynchronous satellites, which typically orbit about 22,000 miles (about 35,000 km). It will skim past the Earth at an altitude of about 17,000 miles (27,000 km), so there are no concerns about an impact, but it could (very unlikely!) take out a satellite on its way through our neighborhood.
It is interesting, and a bit concerning to note that the object that exploded over Tunguska, Siberia in 1908 is estimated to be about 120 feet (36 m) in diameter! Here’s an excerpt from NASA’s site on the event:
“It is estimated the asteroid entered Earth’s atmosphere traveling at a speed of about 33,500 miles per hour. During its quick plunge, the 220-million-pound space rock heated the air surrounding it to 44,500 degrees Fahrenheit. At 7:17 a.m. (local Siberia time), at a height of about 28,000 feet, the combination of pressure and heat caused the asteroid to fragment and annihilate itself, producing a fireball and releasing energy equivalent to about 185 Hiroshima bombs.” – NASA Science News
This leveled over 800 square miles (2072 sq km) of tundra! Imagine that destruction over a major metropolitan area today! Although small, relatively speaking, these objects are moving at very high velocities, which translates into very large amounts of energy that can be released when they explode or impact an object.
Fortunately for us, 2012 DA14’s orbit will cause it to just miss us, but it points out the potential for very catastrophic events to occur from objects that are relatively very small. It was by chance that we discovered it when we did, thanks to work by the Planetary Society.
Our surveillance of the asteroid threat has gotten better, but there is still need for improvement and more importantly, a plan of action to deal with an asteroid that will impact the Earth. This needs to be researched, tested and ready before we find that space rock with our name on it. There is work being done on this, but it is not at the level it should be. We do not know when we might find a potentially lethal asteroid, and we don’t know how much time we will have to deal with it when it is discovered. We need to be prepared. The sooner the better!
Speaking of space rocks destined to impact Earth. The book, ORBITAL MANEUVERS discusses some of the consequences of a very large asteroid impacting the Earth and a stranded space shuttle crew’s attempt to survive the aftermath while in orbit. Part of the reason to write the book was to draw attention to this very real threat. To give more people the chance to read the book and get a sense of what is in store for us should a large impact occur, I’ve reduced the price on the book to $8.95 for the paper back, and $.99 for the electronic versions for Kindle and all other digital formats at Smashwords. It is also available on Apple’s ibooks. Enjoy!
Keep looking up. You never know what you’re going to see!
Till next time,