... COBE Hotspots: The Oldest Structures Known . ... Above are two microwave images of the sky, looking north and south of our galaxy's equator, based on data from NASA's COBE satellite. After computer processing to remove contributions from nearby objects and the effects of the earth's motion, they show "spots". ... Our Earth is not at rest. ... The Sun orbits the center of the Milky Way Galaxy. The Milky Way Galaxy orbits in the Local Group. ... What's the closest galaxy to our Milky Way? ...