"'The threshold has now been crossed,' said astronomer R. Paul Butler of the Carnegie Institution of Washington, one of the planet’s discoverers, in a press briefing Sept. 29. 'The data says this planet is at the right distance for liquid water, and the right mass to hold on to a substantial atmosphere.' The discovery is both 'incremental and monumental,' comments exoplanet expert Sara Seager of MIT, who was not involved in the new study. When a recent study predicted the first habitable world should show up by next May, Seager rightly said the real answer was more like 'any day now.'"