AS102 Study Guide - Final Guide: Fomalhaut, Ecliptic
Document Summary
So, to reiterate, our sun is about 2/3 of the way out from the centre (some. 28,000 ly) with the orbits of the planets (the ecliptic plane) tipped at about 60 to the galactic plane which is why we see the band of the milky way spilled across our sky the way we do. In analogous terms, if the milky way galaxy were the size of the earth, our solar system would be the size of a large cookie. In the large sphere that surrounds the galactic disk and bulge most of the stars are old, red, dim and smaller in mass than our sun. These stars formed early in the galaxy"s history, are long-livers, and have not enriched the halo with heavy- element atoms. Consequently the halo is virtually gas free with few molecular clouds so new stars are rarely born.
