approacher

approach +‎ -er

approacher (plural approachers)

1. Someone or something that approaches.
2. (astronomy) An asteroid on a near-Earth trajectory.
   • 1997 December 19, Erik Asphaug, “PLANETARY SCIENCE: Enhanced: New Views of Asteroids”, in Science‎, volume 278, number 5346, DOI:10.1126/science.278.5346.2070, pages 2070-2071:

     Extensive upgrades to the Arecibo antenna will be completed this spring, providing dozens of Toutatis-quality detections per year, spacecraft-quality images of the closest approachers, and hundred-pixel images of dozens of main-belt asteroids ( 9 ).

   • 2005 June 3, Ted McClelland, “Something Big Is Out There”, in Chicago Reader‎:

     We have some close approachers," he says, "but not one that would have an impact trajectory."

• reapproach