16 Feb
2013
16 Feb
'13
1:14 p.m.
On 2/16/13, Warren Smith <warren.wds@gmail.com> wrote:
The Russian Academy of Sciences estimates the meteor had a mass of 10,000 tons, entered atmosphere at speed 15 km/s and exploded when 30-50 km up. NASA estimated it was 17 meters diameter and 10,000 tons with an energy release equivalent to roughly 500 kilotons of TNT.
--NASA got it wrong, since 500*kiloton = 2.1*10^15 joule = m*v^2 / 2 and with v=15 km/sec, we find m is at least 18666 tonnes ("at least" since not all energy released in the blast).