Discovery and exploration of the Solar System Earth to be orbited by an artificial satellite ("Luna 10"), followed by Mars in 1971 ("Mariner 9"), Venus in 1975 ("Venera 9"), Jupiter in 1995 ("Galileo"), the asteroid 433 Eros in 2000 ("NEAR Shoemaker"), Saturn in 2004 ("Cassini–Huygens"), and Mercury and Vesta in 2011 ("MESSENGER" and "Dawn" respectively). "Dawn" is orbiting the asteroid–dwarf planet Ceres as of 2015. The first probe to land on another Solar System body was the Soviet "Luna 2" probe, which impacted the Moon in 1959. Since then, increasingly distant planets have been reached, with probes landing on or impacting the surfaces of Venus in 1966
History of Solar System formation and evolution hypotheses of dynamics makes capture most unlikely as it requires special conditions. Swiss astronomer Louis Jacot (in 1951, 1962, 1981), like Weisacker and Ter Haar, continued the Cartesian idea of vortices but proposed a hierarchy of vortices or vortices within vortices, i.e., a lunar system vortex, a Solar System vortex, and a galactic vortex. He put forward the notion that planetary orbits are spirals, not circles or ellipses. Jacot also proposed the expansion of galaxies (stars move away from the hub), and that moons move away from their planets. He also maintained that planets were expelled, one at a time, from