The time that it takes to transfer between two of these systems is equal to the square root of the cube of r-one plus r-two over eight times the speed of one body. That is how long a Hohmann transfer takes. One of these around an unstable Lagrange point is known as the halo type. The square of their period is proportional to the cube of their semi-major axis. The aphelion and perihelion lie along 
The time that it takes to transfer between two of these systems is equal to the square root of the cube of r-one plus r-two over eight times the speed of one body. That is how long a Hohmann transfer takes. One of these around an unstable Lagrange point is known as the halo type. The square of their period is proportional to the cube of their semi-major axis. The aphelion and perihelion lie along these paths, which are elliptical according to the first of Kepler's three laws for these systems. For 10 points, what are these paths taken by the planets around a star?
The time that it takes to transfer between two of these systems is equal to the square root of the cube of r-one plus r-two over eight times the speed of one body.
planetary orbits [or orbital motion; or orbiting systems; accept equivalents; prompt on "planetary motion" or equivalents; prompt on "elliptical motion," "ellipse," or equivalents until "elliptical"]