Location of the planetary nebulae in the outskirts of the giant galaxy M87 and in the intergalactic space around the center of the Virgo Cluster of galaxies. By measuring the motions of these objects very precisely, using the highly efficient FLAMES spectrograph on the ESO Very Large Telescope at the Paranal Observatory (Chile), astronomers have probed the edge of M87 for the first time, and they found it to be about three times as large as our own Milky Way.