#solar system
- Ampycus — An ancient proper name (also known as Ampyx or Amphicos) designating several figures in Greek mythology, the most famous being the seer and priest of Apollo, father of the prophet Mopsus; in astronomy, the term represents centaur asteroid number 98127 (98127 Vilă-Ampycus), a minor celestial body with an eccentric orbit located in the outer solar system.
- Aristarchus — A historical proper name borne by prominent figures of Antiquity, the most famous being Aristarchus of Samos, the Greek astronomer who first formulated the heliocentric model of the Solar System, placing the Sun at the center. In a philological sense, it also refers to Aristarchus of Samothrace, a literary critic famous for his rigorous editing of Homeric epics, his name becoming a common noun synonymous with a severe but highly competent critic.
- Asteroid — A rocky or metallic celestial body, much smaller than a planet, orbiting the Sun, with most clustered in the main belt between Mars and Jupiter; as an adjective, it describes an object, organism, or structure exhibiting a stellar shape or star-like radial symmetry.