A planet crossing its star takes a little light. The dip is tiny. Kepler is built to watch the same 150,000 stars, without touring, for years. Borucki’s team has argued for this photometer through decades of refusal. On 7 March 2009 it leaves.

This is not Mayor and Queloz on one wobbling sun. It is a field. The census of worlds becomes a census.

Transits give a radius, not a pretty picture. False positives are many. Follow-up is ground-based. The result, even after the wheels fail, is that planets are ordinary around ordinary stars. 51 Pegasi b was a surprise of kind. Kepler is a surprise of number.