How close can a rocky planet be to a star, and still sustain water and life? A recently discovered exoplanet may be key to solving that mystery, providing important insights about conditions at the inner edge of a star’s habitable zone and why Earth and Venus developed so differently, according to new research led by Lisa Kaltenegger, director of the Carl Sagan Institute and professor of astronomy in the College of Arts and Sciences. “We don’t know what this planet on the edge of habitability could be like, so we have to look,” she said. “This is what real exploration is about.”