B. Edwards

A bus schedule drifts: if you don't check it, you'll miss your ride. Planets around other stars have the same problem – their crossings of the star's disk gradually shift. The ExoClock project pooled 30,000 observations from Earth and space to refine the schedule for 620 distant worlds. For 45% of the planets, transits were found to be off by hours.

When an exoplanet briefly eclipses its star, starlight passes through its air and absorbs its chemical taste. This technique, the transit method, is the core of how the James Webb telescope works.