Sixty years ago the Soviet Union detonated the world’s most powerful nuclear weapon, with a force 3,333 times that of the bomb used on Hiroshima.  Kennedy’s calculated nonresponse to the pushy clamor showed his “deep revulsion for nuclear weapons.  The explosive force of the Soviet device — nicknamed Tsar Bomba, or the Tsar’s bomb, and set off on Oct. 30, 1961 — was 50 megatons, or equal to 50 million tons of conventional explosives.

Read more how a new study offers insights into how the United States reacted to Tsar Bomba, a planet shaker that made the deadly Hiroshima blast look tame.