Physics and Star Wars
To estimate the effects of the second Death Star, Minton looks into its mass. According to estimated data from some students of Lehigh University, the steel mass needed for building one would be around 770 kilograms times the mass cubed in weight. This would give the Death Star of about ten to the power of nineteen kilograms in mass. Using this data, Minton produces equations that lead him to conclude the fragments would hit the moons surface so hard causing craters almost four times the size of the Chicxulub crater in Mexico. This impact would cause a planetary firestorm and vaporize all lifeforms on the moon.
Schwerer Gustav
Schwerer Gustav (English: "Heavy Gustaf") was a German 80 cm (31.5 in.) railway gun. It was developed in the late 1930s by Krupp in Darłowo (then Rügenwalde) as siege artillery for the explicit purpose of destroying the main forts of the French Maginot Line, the strongest fortifications in existence at the time. The fully assembled gun weighed nearly 1,350 tonnes, and could fire shells weighing seven tonnes to a range of . The gun was designed in preparation for the Battle of France, but was not ready for action when the battle began, and in any case the Wehrmacht's Blitzkrieg offensive through Belgium rapidly outflanked and isolated the Maginot Line's static defenses, eventually forcing the French to surrender and making their destruction unnecessary. Gustav was later deployed in the Soviet Union during the Battle of Sevastopol, part of Operation Barbarossa, where, among other things, it destroyed a munitions depot located roughly 30 meters below ground level. The gun was moved to Leningrad, and may have been intended to be used in the Warsaw Uprising like other German heavy siege pieces, but the rebellion was crushed before it could be prepared to fire. Gustav was destroyed by the Germans near the end of the war in 1945 to avoid capture by the Red Army.