Standard Planetary Mass

A Standard Planetary Mass (spm) was a comparative unit of measurement, used to measure the masses of planets and similar sized objects. The value of this measurement represented the average mass of a terrestrial planet on which life (and therefore civilization) developed. Most habitable and inhabited planets were close to this size.

One ssm was equivalent to around 0.000003 standard stellar masses (ssm) or 6,000,000,000,000,000,000,000 (6x10^21, six sextillion) tonnes.

Behind the Scenes
Equals approximately one Earth Mass.