Encke, Wirtanen, 67P/Churyumov-Gerasimenko, Wild 2, Borrelly, and Tempel 1 — six of the most famous short-period comets — share the inner Solar System with Mercury, Venus, Earth, Mars, and Jupiter. Encke's 3.3-year orbit makes it the shortest-period comet known; 67P was orbited by ESA's Rosetta spacecraft in 2014–2016; Tempel 1 was struck by NASA's Deep Impact probe in 2005. Wirtanen made a spectacular close approach to Earth in December 2018, visible to the naked eye. These comets are thought to originate from the Kuiper Belt or scattered disc, captured into short-period paths by Jupiter's gravity. Positions and velocities are from JPL Horizons.