Celestia Forums

Thanks

I'm experimenting with double planet systems.

I know how to calculate mean distances to center of mass. What I'm not so sure about is orbit eccentricity : is it the same for both planets? If not, how can one be calculated from the other?

What's the problem with fictional planets existing along real ones around a real star? Just imagine : you've written a story about fictional characters living in a real place where you've never been, say Berlin. Then one day you discover that there are actually real people living in Berlin. :wink: D...