And thus "right ascension" is measured in minutes (and hours). Astronomers don't use degrees to measure "longitude" (right ascension) on the celestial sphere.

And thus "right ascension" is measured in minutes (and hours). Astronomers don't use degrees to measure "longitude" (right ascension) on the celestial sphere. Face North (at night) and look right. Everything on that side ascends. In astronomy, East-West distances are measured by how long it takes things to rotate past a fixed observational direction. Every night, a slightly different chunk of sky will also be directly overhead at midnight, due to the difference observed earlier between solar (sun-relative) day length and sidereal (star-relative) day length.