Asteroid 433 Eros: The Target Body of the NEAR MissionAsteroid 433 Eros was the first near-Earth asteroid to be discovered and nearly 100 years of ground-based observations have allowed a rough physical characterization of the body. At the time of the NEAR spacecraft arrival in early 1999, the Eros ephemeris uncertainties will be less than 50 km based on ground-based astrometric observations alone. Characteristics are described.