1. The problem statement, all variables and given/known data The star alpha centauri is 4.25 light years from us, so it takes its light 4.25 years to reach earth. It is impossible, in principle, for any rocket from earth ever to reach this star in less than 4.25 light years. 2. Relevant equations 3. The attempt at a solution My first answer was that the statement was false as length contraction would make the journey distance shorter for rockets F.O.R and the accepted answer is true, which leads me to the conclusion that they must mean 4.25years in earth's F.O.R I would like to know how I could identify in which frame they requested the answer in the problem above.