Tsar Bomba C), north of the Arctic Circle over the Novaya Zemlya archipelago in the Arctic Ocean. The bomb was dropped from an altitude of ; it was designed to detonate at a height of over the land surface ( above sea level) by barometric sensors. The original, November 1961, United States Atomic Energy Commission estimate of the yield was 55–60 megatons, but since 1992, all Russian sources have stated its yield as 58.6 megatons. First secretary Khrushchev warned in a filmed speech to the Supreme Soviet of the existence of a 100-megaton bomb (technically the design was capable of this yield.)
Novaya Zemlya effect two full weeks prior to its calculated return. They were met with disbelief by the rest of the crew (who accused De Veer of having used the old Julian calendar instead of the Gregorian calendar introduced several years earlier), but on January 27 the Sun was seen by all "in his full roundnesse". For centuries the account was the source of skepticism, until in the 20th century the phenomenon was finally proven to be genuine. Apart from the image of the Sun, the Novaya Zemlya effect can also elevate the image of other objects above the horizon, such as coastlines