choice: planet orbit
choice: planet sun
choice: planet elliptical
choice: sun elliptical
choice: planet space
choice: planet gravity
choice: planet attracts
choice: orbit sun
choice: orbit elliptical
choice: orbit space
choice: orbit gravity
choice: orbit attracts
choice: sun space
choice: sun gravity
choice: sun attracts
choice: elliptical space
choice: elliptical gravity
choice: elliptical attracts
choice: space gravity
choice: space attracts
choice: gravity attracts