Kepler-36 c

The outer hot gas sub-giant world in the Kepler-36 system, Kepler-36 c orbits Kepler-36 about once each 16 days at a distance of 12 million miles, along with the inner rocky world Kepler-36 b.

The two planets experience a conjunction every 97 days on average. The timing of their orbits means they'll never collide, however, the continuous close encounters cause tremendous gravitational tides that squeeze and stretch both planets.

The larger planet likely has a rocky core surrounded by a substantial amount of atmospheric hydrogen and helium. The planets' densities differ by a factor of eight but their orbits differ by only 10 percent.