Scale: 1020 meters = 100 Em = 100 exametersOur Spiral ArmThe Sun is located near the inner edge of one of the spiral arms of the Milky Way, the Orion Arm -- situated between the Sagittarius Arm to the inside and the Perseus Arm to the outside. More specifically, we seem to be located near the middle of a small spur off the inner edge of the Orion Arm called Gould's Belt. This information has been pieced together from studying the proper motion of nearby stars, radio observations of interstellar hydrogen clouds, and the careful mapping of many of the stars of our nighttime sky. At this scale, from 20 000 light years away, the Sun is much too faint to be visible. We won't be able to detect the Sun with the naked eye for another three jumps -- we need to get within 50 light years to be able to see our star. Copyright © 2016 by Bruce Bryson |