What is the longest unit of length?
Approved answer
Understanding the Parsecs
A parsec, or parallactic second, is defined as the distance at which an arc measuring one astronomical unit creates an angle of one second from a given point of observation. Specifically, 1 parsec is equal to approximately 3.1 × 1016 meters or about 3.26 light-years. Furthermore, 1 parsec corresponds to 206,265 astronomical units (AU), making it the largest known unit of length.