Saturday, May 11, 2013

Russian Asteroid Impact: FAQ on the 15-Feb-2013 Chelyabinsk Event

Q: What kind of object struck central Russia early on Friday, February 15th?

A: It was a "near-Earth object" (NEO), an asteroid (likely made of rock) between 15 and 20 meters across (about the length of a school bus),...

which just happened to arrive in the same place as planet Earth that morning. [!!!]

The mass of the object was about 10 thousand tons.

It struck the atmosphere moving at about 40,000 MPH (more than double the speed of the Space Shuttle).

Q: How big was the blast from the Russian event and why did the asteroid explode before hitting the ground?

A: Scientists are still analyzing records of the Feb. 15th event, but preliminary indications derived from infrasound instruments around the world established to monitor potential nuclear bomb tests suggest the explosion was about the equivalent of half a megaton of TNT, or approximately 30 Hiroshima A-bombs exploding at once.

The asteroid exploded in midair at high altitude (early reports suggest about 30 miles high).

Hitting anything at 40000 MPH, even air, is like hitting concrete.

The enormous deceleration and pressure of hitting the atmosphere ripped apart the asteroid.

Most rocky asteroids of this size that strike Earth explode in midair.

Fragments of the asteroid after the explosion rained down in the vicinity.

[More Q&A]