Today marks the three-year anniversary of the Chelyabinsk asteroid airburst. You probably recall watching the dash cam video footage of the fireball exploding over the city. The asteroid was only 17-20 meters in diameter. For reference, the asteroid that flattened 2,000 sq km of forest in Tunguska, Siberia in 1908 was somewhere around 45 meters in diameter. The explosion above Chelyabinsk generated an intense flash momentarily brighter than the sun and had a total kinetic energy of about 500 kilotons of TNT, which is approximately 20-30 times the energy released by the atomic bomb in Hiroshima. About 1,500 people were injured and over 7,200 buildings in six cities were damaged by the explosion’s shock wave. And we had no advance notice.  

And advance notice is what we need in order to successfully deflect an asteroid. The good news is that the situation is about to improve greatly. Construction has already begun on the National Science Foundation funded Large Synoptic Survey Telescope in Chile. Mission Scientist Marc Buie and Mission Director Harold Reitsma have even shown that Sentinel together with LSST can be combined to find more than 70% of impacting asteroids larger than the Tunguska asteroid. This work has been submitted for publication, and we will share the paper with the wider asteroid community in the near future.

Today, let’s take a moment to remember just how important early detection is.