In the United States, domestic weapons recycling programs are smaller in scale and would be no replacement for Megatons for Megawatts.

In the event, it may have yielded 57 megatons - which would have made it just under four times as destructive as the Tunguska meteorite.

The blast, which has been estimated at the equivalent of around 15 megatons of TNT is widely thought to have been caused by a meteor a few tens of metres across exploding in mid-air.