Nearby in Balaclava (yes, the hat is named after this place - look it up), a submarine base is cut out of the side of a mountain, making it invisible to surveillance and able to withstand a 10 megaton nuclear explosion.
The largest weapon of this kind known to have been tested was estimated to be a 58 megaton (58 million tonnes of TNT) device produced by the Soviet Union during the height of the cold war.
Were the asteroid to hit Earth, it would enter the atmosphere at nearly 103,000 km/h and strike with the explosive energy of 1.2 million megatons of TNT.
In a nightmare future of nuclear conflict, megatonnage would matter.
Oil and coal were fast becoming memories, and incredible advances in solar power had come to nothing, due to greenhouse clouds and the megatonnage of dirt thrown into the atmosphere by the Nine Days War.
The blast, called a solar flare, was equal to one million megatons of TNT and gave off powerful bursts of X-rays.
Some news accounts warned that its explosive force upon impact would be 350,000 megatons , eight million times more powerful than the Hiroshima bomb.