Venus is the brightest planet, reaching magnitude -4.4 at greatest brilliance — bright enough to cast shadows and be seen in full daylight if you know where to look. It shows a complete cycle of phases visible in binoculars: a tiny full disk near superior conjunction, a dramatic thin crescent when closest to Earth (up to 66 arcsec across). Galileo first observed these phases in 1610, providing key evidence for the Copernican model. As the morning or evening star, Venus dominates the twilight sky, reaching up to 47 degrees elongation. The Babylonians tracked it on the Venus tablet of Ammisaduqa around 1600 BCE. Named for the Roman goddess of love and beauty. The Soviet Venera program achieved remarkable firsts: Venera 7 landed in 1970 (first successful landing on another planet), and Venera 9 returned the first surface photographs in 1975. Magellan radar-mapped 98% of the surface from orbit in 1990-94, revealing a landscape of volcanic plains, massive shield volcanoes (Maat Mons, 8 km high), and continent-sized highlands. The dense CO2 atmosphere creates a runaway greenhouse effect with surface temperatures of 465C and 90 bar pressure. Through a UV filter, cloud-top banding is visible in modest telescopes.