History of Astronomy

accepted accurate ancient appear astronomers attraction bodies bright calculations called catalogue cause centre century Chinese circle comet compared complete Copernicus determined diameter direction discovered discovery distance earth eclipse effect elements enabled epicycles equal error explain fact fixed follow force four Galileo gave give given gravitation heavens held Herschel increased interesting Jupiter Kepler knowledge known later light lunar Mars mass mathematical mean measured method miles moon moon's motion move nebulæ Newton noted noticed object observations Observatory opposition orbit original parallax pass period photographic physical planet planetary pole position predicted progress proper motion proved records researches revolve ring rotation round Royal satellites seems seen showed solar system spectroscope spectrum stars studied sun's supposed surface tables telescope theory tion trace true Tycho Brahe UNIVERSITY