The issue focused on NASA's Kepler spacecraft which searches for planets orbiting distant stars using its gravitational lens effect to peer closer than usual into space. Kepler searches for planetary candidates using three infrared wavelengths – infrared light emitted from planetary surfaces – looking for dips in brightness caused when planets cross their orbits around other stars. Scientists discovered Kepler-438b when analyzing Kepler data collected during its initial planetary detection mission and subsequently correlated its spectral fingerprint with planetary transit measurements obtained during Kepler's subsequent planetary detection mission. Kepler-438b orbits its star