Example image of eyePlorer eyePlorer map for 'Light-year': International Astronomical Union Julian year (astronomy) Light Vacuum Length Units of measurement Galaxy Popular science Astrometry Parsec Astronomical unit Minute of arc Parallax Astronomical constant Gregorian calendar International System of Units Kilometre Metre Speed of light DE400 Astronomical system of units Month Tropical year Ephemeris time Epoch (astronomy) Significant figures Simon Newcomb Star system Globular cluster Spiral galaxy Star Galaxy groups and clusters 1000000000 (number) CfA2 Great Wall Quasar 1 petametre 1 yottametre 1 zettametre 10 exametres 10 petametres 10 Vulpeculae 10 yottametres 10 zettametres 100 exametres 100 petametres 100 yottametres 100 zettametres 107 Piscium 109 Piscium 11 Aquarii