Astronomy
Astronomy (from Greek: ἀστρονομία) is a natural science that studies celestial objects and phenomena. It applies mathematics, physics, and chemistry, in an effort to explain the origin of those objects and phenomena and their evolution. Objects of interest include planets, moons, stars, galaxies, and comets; the phenomena include supernova explosions, gamma ray bursts, and cosmic microwave background radiation. More generally, all phenomena that originate outside Earth's atmosphere are within the purview of astronomy. A related but distinct subject, physical cosmology, is concerned with the study of the Universe as a whole.
Physics
Physics (from Ancient Greek: φυσική (ἐπιστήμη), translit. physikḗ (epistḗmē), lit. 'knowledge of nature', from φύσις phýsis "nature") is the natural science that studies matter and its motion and behavior through space and time and that studies the related entities of energy and force. Physics is one of the most fundamental scientific disciplines, and its main goal is to understand how the universe behaves.
Astronomy
It's unique because it doesn't look like a comet with the typical tail; it looks like a cloud. It's not what you would normally see at all … With the naked eye, it looks like a star or planet, but with binoculars it's really weird looking; it doesn't happen every day.
George Masterson, physics and astronomy teacher on Comet 17P/Holmes - quoted in "Mysteriously bright comet provides sky-high teaching moment at NHS" in the Daily News of Newburyport (9 November 2007).
Physics
Theoretical physicists live in a classical world, looking out into a quantum-mechanical world. The latter we describe only subjectively, in terms of procedures and results in our classical domain.
John Stewart Bell "Introduction to the hidden-variable question" (1971), included in Speakable and Unspeakable in Quantum Mechanics (1987), p. 29
