By Ron Cowen
For 89 years, astronomers have played a cosmic version of Where’s Waldo? Now, the game is over.
Scientists have rediscovered a near-Earth asteroid called 719 Albert, observed several times in 1911 but not seen since. Its number indicates that Albert was the 719th asteroid to have its orbit determined, a bookkeeping convention that began in 1801 with Ceres, the first asteroid identified. With Albert’s rediscovery, scientists finally know the whereabouts of all 14,788 numbered asteroids.