2. According to NASA, Proxima Centauri, a red dwarf star, is 4.244 light-years from the Earth. According to a spaceman in a rocket moving between the Earth and Proxima Centauri, the star is 0.65 light-years from the Earth. a Outline why the distance quoted by Nasa to Proxima Centauri is a proper length. [1] b Calculate the Lorentz factor, y, for the rocket. [1] c Calculate the speed of the rocket relative to the speed of light [2]