| light-year (ly) | 63241 AU | 9.461×1015m or 5.879×1012 miles |
| parsec | 3.262 ly | 206,265 AU, 3×1016m or 1.917×1013 miles |
| speed of light | 186,000 miles/sec | 300,000 km/sec |
| Earth radius | 3959 miles | 6371 km |
| Earth mass | 5.972×1024 kg | |
| Earth orbital speed | 30 km/sec | 67100 MPH |
| Moon distance | 238,900 miles | 60 Earth radii, 0.55 solar radius or 0.0025 AU |
| Moon radius | 1079 miles | 0.27 Earth radius (1/4) or 1037 km |
| Moon mass | 7.3×1022 kg | 0.012 Earth mass (1.2%) |
| Moon orbital speed | 1 km/s | 2200 MPH |
| Sun distance | 93 million miles | 215 solar radii or 1 AU |
| Sun radius | 432,288 miles | 109 Earth radii or 0.0047 AU |
| Sun mass | 2×1030 kg | 334,000 Earth masses |
| Jupiter orbit radius | 483.8 million miles | 5.2 AU |
| Jupiter radius | 43441 miles | 11 Earth radii or 1/10 solar radius |
| Jupiter mass | 1.898×1027 kg | 318 Earth masses or 0.001 solar mass (0.1%) |
| Neptune orbit radius | 2.795 billion miles | 30 AU, 0.0005 ly or 4hr20min × c |
| Neptune radius | 15299 miles | 3.85 Earth radii or 0.035 solar radius (3.5%) |
| Neptune mass | 1026 kg | 17 Earth masses or 0.00005 solar mass (0.005%) |
| Alpha Centauri distance | 4.367 ly | 9200 × Neptune's orbit radius |
| galactic center distance | 26000 ly | 8.2 kpc or 6000 × distance to Alpha Centauri |
| Milky Way number of stars | 100-400 billion | |
| Milky Way visible diameter | 100,000 ly | 30 kpc |
| Milky Way visible depth | 10,000 ly | 3 kpc |
| Milky Way galactic halo diameter | 300,000-400,000 ly | 100 kpc |
| Canis Major Dwarf Galaxy distance (claimed nearest galaxy) | 25000 ly | 8 kpc |
| Sagittarius Dwarf Elliptical Galaxy (accepted nearest galaxy) | 81000 ly | 25 kpc |
| Andromeda distance (nearest similar galaxy) | 2.537 million ly | 778 kpc, 0.8 Mpc or 25 Milky Way diameters |
| Local Group diameter | 10 Mly | 3 Mpc or 100 Milky Way diameters |
| Local Group galaxy count | 54 | |
| Virgo Cluster (nearest galaxy cluster) distance | 59 Mly | 18 Mpc |
| Virgo cluster galaxy count | 1000-2000 | |
| Virgo Supercluster diameter | 110 Mly | 34 Mpc |
| Virgo supercluster cluster/group count | 100 | |
| Virgo supercluster galaxy count | 47000 | |
| Laniakea Supercluster diameter | 520 Mly | 160 Mpc or distance to z = 0.04 |
| Laniakea cluster count | 300-500 | |
| Laniakea galaxy count | 100,000 | |
| typical stars per galaxy | billions to 100 trillion | |
| superclusters in observable universe | estimated 10 million | |
| galaxies in observable universe | estimated 170 billion | |
| stars in the observable universe | estimated 1024 (septillion) | |
| age of universe | 13.82 gigayears | |
| diameter of observable universe | 93 Gly | 28.5 Gpc or 180 × Laniakea radius |
| mass of observable universe | estimated 1053kg | |
| visible light wavelengths | 4000-7000 angstroms | 4×10-7 to 7×10-7 meters |
| atoms in a gram of hydrogen (Avogadro's number) | 6.022×1023 | |
| atoms in the universe | estimated 1078 to 1082 | |
| photons in the universe | estimated 1089 | |
| neutrino density | 340/cm3 | |
| neutrinos in the universe | estimated 1.2×1089 | |
| atomic density of the universe (baryonic mass density) | estimated 0.2-0.25 hydrogen atoms/meter3 | |
| critical density of the universe | estimated 5 hydrogen atoms/meter3 | threshold between eventual expansion versus collapse |
| density including dark matter and dark energy | roughly same | very close to critical density |