Milky Way galaxy. Computer artwork of the Milky Way galaxy (top),which contains our solar system (bottom). Our solar system comprises of eight planets orbiting our Sun (including Earth),only four of which are shown here. The Milky Way is a spiral galaxy. It has a central bulge (yellow) of old stars that has a bar (white) of older,redder stars passing through it. Around this nucleus,10,000 to 16,000 light years away,is a bright 'molecular ring' (blue) of young hot stars and star forming regions. The spiral arms extend outwards from this ring. Our Sun is 28,000 light years from the galactic centre,taking about 220 million years to complete an orbit. It is currently in the Orion arm of the Milky Way |