... The Galactic Center Radio Arc . ... What causes this unusual structure near the center of our Galaxy? ... The Tarantula Nebula is more than 1,000 light-years in diameter -- a giant star forming region within our neighboring galaxy the Large Magellanic Cloud (LMC). That cosmic arachnid lies at the upper left of this expansive mosiac covering a part of the LMC over 6,000 light-years across. ... Bright lenticular galaxy M86 is near center of this cosmic view, at the heart of the Virgo Galaxy Cluster. ...