speed of light (c) 6.674 × 10 −11 m 3 /(kg s 2 ) mass of a hydrogen atom (M H ) mass of an electron (M e ) energy equivalent of 1 ton TNT mass of Earth (M Earth ) equatorial radius of Earth (R Earth )...speed of light (c) 6.674 × 10 −11 m 3 /(kg s 2 ) mass of a hydrogen atom (M H ) mass of an electron (M e ) energy equivalent of 1 ton TNT mass of Earth (M Earth ) equatorial radius of Earth (R Earth ) surface gravity of Earth (g) escape velocity of Earth (v Earth ) mass of Sun (M Sun ) equatorial radius of Sun (R Sun ) luminosity of Sun (L Sun ) solar constant (flux of energy received at Earth) (S) approximately 20 km/s per million light-years, or approximately 70 km/s per megaparsec
speed of light (c) 6.674 × 10 −11 m 3 /(kg s 2 ) mass of a hydrogen atom (M H ) mass of an electron (M e ) energy equivalent of 1 ton TNT mass of Earth (M Earth ) equatorial radius of Earth (R Earth )...speed of light (c) 6.674 × 10 −11 m 3 /(kg s 2 ) mass of a hydrogen atom (M H ) mass of an electron (M e ) energy equivalent of 1 ton TNT mass of Earth (M Earth ) equatorial radius of Earth (R Earth ) surface gravity of Earth (g) escape velocity of Earth (v Earth ) mass of Sun (M Sun ) equatorial radius of Sun (R Sun ) luminosity of Sun (L Sun ) solar constant (flux of energy received at Earth) (S) approximately 20 km/s per million light-years, or approximately 70 km/s per megaparsec