The 1883 eruption of the Krakatoa
volcano
.
It is the most terrifying natural event ever: the volcanic eruption of Krakatoa ( Indonesia ) had a power of 200 megatons , 21 cubic km of incandescent material were expelled and the glow, sound and effects of the explosion were detectable as far away as South Africa and Australia .
The enormous explosion had a shock force equal to 4 times that of the ' Tsar Bomba ' (the most powerful war device ever created by man ), which caused an impressive number of victims: 36,000, equal to approximately 165 human villages completely wiped off the face of the Earth.
The bluish reflection present today on the visible face of the Moon
is due precisely to the abnormal release of ash caused by the explosion.