AidanThomas

I highly recommend Kahn Academy - They have everything Academic on there with tutorial videos broken down into small and easy steps. https://www.khanacademy.org/ - Enjoy mate

The Siderial Period - This is the time required for a celestial body within the solar system to complete one revolution with respect to the fixed stars. The synodic period - This is a rotation of a planet so that it appears to be in the same place in the night sky. Taking into consideration that this object could be smaller than earth but has twice the orbital radius. All you need to figure out is the Siderial and Synodic Periods of earth. From there you can figure out but doubling.