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.
Doomsday device
Doomsday devices started becoming more common in science fiction in the 1940s and 1950s, due to the invention of nuclear weapons and the constant fear of total destruction. A well-known example is in the film "Dr. Strangelove" (1964), where the Dead Hand is triggered by an incompletely aborted American attack, and all life on Earth is extinguished. Another is in the TV episode "" (1967), where the crew of the "Enterprise" fights a powerful planet-killing alien machine. However, doomsday devices also expanded to encompass many other types of fictional technology, one of the most famous of which is the Death Star, a moon-sized planet-destroying space station.