|
|
|
|
|
|
Zettameter is an SI device for measuring distance. It is equal to 1021 meters. The symbol for zettameter is Zm.
The spat (symbol S) is also an obsolete unit of distance used in astronomy. It is equal to 1000000000 kilometres (1 Tm or 1012 m). It is about 6.6846 astronomical units (AU), 1.057×10−4 light-years or3.240×10−5 parsecs.