Earth mass (M⊕, where ⊕ is the standard astronomical symbol for planet Earth) is the unit of mass equal to that of Earth. This value includes the atmosphere but excludes the moon. The current best estimate for Earth mass is M⊕ = 7024597220000000000♠(5.9722±0.0006)×1024 kg Earth mass is a standard unit of mass in astronomy that is used to indicate the masses of other planets, including rocky terrestrial planets and exoplanets. 1 Value.