1. The problem statement, all variables and given/known data An asteroid revolves around the sun with a mean orbital radius twice that of Earth's. Predict the period of the asteroid in Earth years 2. Relevant equations I guess t^2/r^3 where t = period and r = mean orbital radius 3. The attempt at a solution I missed the lecture in class, and I'm ultimately confused on the subject of Orbital Dynamics and Kepler's Law, any help/explanation would be great, or a link to a useful website, honestly I'm clueless. I think the fact that the r for the asteroid is twice as long as earth's creates a ratio?