Ivar is a large Mars-crosser asteroid that was discovered in 1929 by Ejnar Hertzsprung at Johannesburg, South Africa. Although it does not cross Earth's orbit, during 1900-2100 it comes closer to the Earth with its 2074 pass at 21.1 Gm (0.141 AU) than it does to Mars (22.5 Gm or 0.150 AU in 1975).