GALACTIC TAGALONGS? The Milky Way arches above Paranal Observatory in Chile, accompanied by the Large and Small Magellanic Clouds (fuzzy objects at center, below galactic disk). The view is deceptive: Recent research has revealed that the Large Magellanic Cloud is more massive and more influential on our galaxy than previously thought. Giant A combination of new data and tenacity has upended our understanding of the Milky Way's largest companion. and others used new data from the Hubble Space Telescope to calculate how fast the LMC was moving by tracing its path across several background quasars over the course of four years. To their surprise, they found that the galaxy was not lazily falling toward the Milky Way - it was rushing past it. A year later, Gurtina Besla (now University of Arizona), Kallivayalil, and their collaborators combined the observations with simulations to argue that the LMC was likely falling toward us for the first time, rather than making its fifth or six passage, as previously supposed (S&T: Oct. 2012, p. 28). Later work also suggested that the LMC must be far more massive than scientists had long believed. A heftier cloud should do more damage to the Milky Way; Say What ? perigalacticon: the closest approach to a galaxy sk yandtelescope.org * JUNE 2 021 21http://www.skyandtelescope.org