The Milky Way has two satellitegalaxies, the Large and Small Magellanic
Clouds. The orbits of these galaxies tells us that the mass in the halo
around the Milky Way is 5 to 10 times greater than the mass we can
Imagine the Universe is a service of the High Energy Astrophysics Science Archive Research Center (HEASARC), Dr. Alan Smale (Director), within the Astrophysics Science Division (ASD) at NASA's Goddard Space Flight Center.