Consider the Oort clound to consist of a large number of comets at a distance from the Sun where the period of a circular orbit around the Sun would be a million years.
1. What is the radius of this orbit?
2. If a comet in this orbit is perturbed, therefore that its new orbit has an aphelion at its original orbital radius, however now a perihelion at 0.3AU, how long will it take to reach its perihelion?