Two studies of an Earth-sized planet circling the sun-like star Kepler-78 show it has Earth-like amounts of iron and rock, the first world of its size that scientists have been able to calculate both density and diameter.
But don't pack your bags yet. The planet, known as Kepler-78b, circles sizzlingly close to its parent star, far from an Earth-like water-friendly orbit, a condition that is believed to be necessary for life.
ANALYSIS: Kepler-78b: Mystery Exoplanet Shouldn't Even Exist
"To me this means that planets like the Earth are probably not all that uncommon," astronomer Drake Deming, with the University of Maryland, told Discovery News.
"If one of the first measurements you're able to make that really pins down the density of a small, rocky planet gives you a density close to Earth's, Earth can't be that rare in terms of density," Deming said.
Two independent teams came up with nearly the same assessment of Kepler-78b, which was discovered last spring by another group of astronomers using data collected by NASA's now-defunct Kepler space telescope.