1. The problem statement, all variables and given/known data The identical twins Speedo and Goslo join a migration from the Earth to Planet X, 19.0 ly away in a reference frame in which both planets are at rest. The twins, of the same age, depart at the same moment on different spacecraft. Speedo's spacecraft travels steadily at 0.945c and Goslo's at 0.625c. (a) Calculate the age difference between the twins after Goslo's spacecraft lands on Planet X in years. (b) Which twin is older? 2. Relevant equations 3. The attempt at a solution Not really sure how to attempt this, im assuming that the speed of the space craft, 0.945c means 0.945 times the speed of light? this is a guess but would you calculate the time it takes each spacecraft to get to Planet X and then the difference in those times would then be the difference in the twins age ?