Planets orbiting the massive star on the left move faster in their orbits than those orbiting at the same distance from the less massive star on the right.

• Blue planets' distances are equal.
• Left star mass = 2 × right star mass.
• Red planet's speed and right blue planet's speed are equal. Red planet's distance = 2 × blue planet's distance.
• Red planet's orbital period is MORE than 2 × (inner left blue planet's orbital period).
  Kepler's 3rd law: P ~ r^3/2 (not P ~ r !)