WASHINGTON—Marking the first time in history that humans have successfully smoothed away all the unsightly craters of a celestial body, NASA announced Thursday that it had polished the moon using an orbital rock tumbler. “Thanks to the tireless efforts of our scientists, technicians, and engineers, we have tumbled the moon in a large machine floating in synchronous rotation with the planet, giving our only natural satellite the luster of a fine-quality gem,” said NASA administrator Bill Nelson, explaining that the $2.5 billion mission to make the moon vibrant and blemish-free began 15 years ago and did not end until it was shiny enough for the earth’s reflection to be seen on its surface. “When you look up tonight and gaze upon the moon, know that it was human ingenuity and hard work that gave it that extra twinkle.” At press time, astronomers had spotted a few remaining imperfections through their telescopes, and NASA was reportedly planning to send astronauts to the moon for a final hand-polish with 2,000-grit sandpaper.