On the morning of Friday, February 15th, the planet Earth was once again reminded of its vulnerability to the dangers of the universe. An estimated 10,000-ton meteor exploded over the skies of the southern Russian city of Chelyabinsk, releasing nearly 500 kilotons of energy from its entry into Earth’s atmosphere to its airborne disintegration. With injury estimates exceeding 1,000 and a reported 3,000 buildings damaged, it is a staunch reminder of the dangers and risks that we carry every day.
At about 17 meters (55 feet) wide, this meteor is alarmingly small by cosmic standards, described by NASA scientists as a “tiny asteroid.” However it is the largest reported meteor since 1908, when an estimated 100-meter (330-foot) meteor – the largest in recorded history – exploded near the Tunguska River in what is now Krasnoyarsk Krai, Russia. Paul Chodas of NASA’s Near-Earth Object Program Office at the Jet Propulsion Laboratory in Pasadena, CA said an event of this magnitude is expected to occur “once every 100 years on average.” It seems we were due for such an event, and probably should have been expecting it.
The event came less than 24 hours away from the closest approach of 2012 DA14, a 190,000-ton asteroid. 2012 DA14, discovered just last year by amateur astronomers in Spain, will swoop down towards Earth, coming within 17,200 miles of its surface. Our own communications satellites watched as it came within a hair’s breadth of Earth by astronomical standards. If this asteroid were to impact our planet, it could release an explosion around three megatons — almost 200 times more powerful than the blast from the atomic bomb at Hiroshima. While astronomers have been able to determine that 2012 DA14 will not impact us in the future, we should see this flyby as a cautionary reminder of the imminent and omnipresent dangers just outside our atmosphere.