Without getting ahead of my story, let’s just say that nearly every planet and moon that ever existed in the solar system was consumed by something bigger than itself, and that makes all the difference in the world. Most planets are now inside of a gas giant (Jupiter or Saturn), or inside the Sun; others are inside of Uranus and Neptune. Two or three additional Neptune-mass giants are believed to have existed that were consumed by the Sun or else ejected to roam the galaxy. Diversity is a matter of perspective, of what’s left: we don’t behold any ordinary planets. Almost every planet that ever existed was consumed by something greater; what’s left are the fortunate and the unusual survivors. WHEN THE EARTH HAD TWO MOONS