Many-armed and dangerousX-ray: NASA/CXC/Caltech/P.Ogle et al; Optical: NASA/STScI & R.Gendler; IR: NASA/JPL-Caltech; Radio: NSF/NRAO/VLABy Joshua SokolJust beyond the Local Group of galaxies that surround our Milky Way, where our map of the cosmos once plunged off an edge and into the unknown, lurks a galactic sea monster. Weirdo galaxy NGC 4258 has...