WEBVTT FILE 1 00:00:00.060 --> 00:00:05.100 ♪Music♪ 2 00:00:05.120 --> 00:00:12.160 M31, the Andromeda Galaxy, is the closest galaxy like our own 3 00:00:12.180 --> 00:00:14.270 ♪Music♪ 4 00:00:14.290 --> 00:00:21.310 Now, NASA's Fermi mission reports a strange gamma-ray signal at its center 5 00:00:21.330 --> 00:00:26.410 ♪Music♪ 6 00:00:26.430 --> 00:00:32.510 This could be a signal of mysterious dark matter 7 00:00:32.530 --> 00:00:39.640 Or the collective glow of many spinning neutron stars, called pulsars 8 00:00:39.660 --> 00:00:45.750 Astronomers don't yet know 9 00:00:45.770 --> 00:00:51.840 Fermi has found a similar unexplained signal at the center of our own galaxy 10 00:00:51.860 --> 00:00:59.940 By exploring M31, Fermi may be able to tell us what's going on much closer to home 11 00:00:59.960 --> 00:01:10.317 [Beeping]