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.
Star Wars: Lost Stars
After their graduation, Ciena was assigned to Darth Vader's Star Destroyer, while Thane was assigned to the Death Star as TIE pilot. Both Thane and Ciena watched when Alderaan was destroyed by the Death Star. Both survived the destruction of the Death Star, because Thane was on assignment to investigate the rebel base at Dantooine and Ciena was on board a Star Destroyer.