astrophotography (n.)

element active in English word formation from mid-18c. and meaning "star or celestial body; outer space," from Greek astro-, stem and combining form of astron "star," which is related to aster "star," from PIE root *ster- (2) "star." In ancient Greek, aster typically was "a star" and astron mostly in plural, "the stars." In singular it mostly meant "Sirius" (the brightest star).

"the art of producing images by application of chemical changes produced by certain substances by the action of light or other radiant energy," 1839, from photo- + -graphy. See photograph.