Kepler Planets: Back to the Origin

The thousands of planet candidates discovered by the Kepler satellite have brought about new insights on planet formation. The close-in Kepler planets have typical masses of order 10 Earth masses, with densities that span two orders of magnitude. Most, if not all, of them are overlaid with some small amount of hydrogen atmospheres at birth. Their orbits tend to be closely packed, and nearly coplanar/circular.  I will briefly review how these conclusions are obtained, before focussing on discuss what implications these results place for the formation environment.