Death Star
The Death Star is a type of fictional mobile space station and galactic superweapon featured in the "Star Wars" space opera franchise. The first Death Star is stated to be more than 100 km to 160 km in diameter, depending on source. It is crewed by an estimated 1.7 million military personnel and 400,000 droids. The second Death Star is significantly larger, between 160 km to 900 km in diameter depending on source, and technologically more powerful than its predecessor. Both versions of these moon-sized fortresses are designed for massive power-projection capabilities, capable of destroying multiple naval fleets or entire planets with one blast from their superlasers.
Physics and Star Wars
Minton therefore concludes there would be little vaporization of remaining material and that the explosion would move a lot slower than what is required to keep them in orbit, which he estimates is about 212 miles per second. Using the equation representing orbital velocity of the Death Star, he theorizes the fragments would need to be orbiting at about 4.5 kilometers per second to maintain orbit at the same altitude the Death Star had been. Since this does not happen, he argues the remains of the former Death Star would fall straight into the area where the shield generator has been on the moon's surface.