We’ve heard many new planet detections — now astronomers also include non-detections for some robust statistics. Conclusion: the average number of planets around a star is greater than one, so they are the rule rather than the exception.

“We used to think that the Earth might be unique in our galaxy. But now it seems that there are literally billions of planets with masses similar to Earth orbiting stars in the Milky Way,” concludes Daniel Kubas, co-lead author of the paper.