page_title: 19P/Borrelly
section_title: Deep Space 1 flyby
hierarchical_section_title: 19P/Borrelly / Deep Space 1 flyby
context_page_description: Comet Borrelly or Borrelly's Comet is a periodic comet, which was visited by the spacecraft Deep Space 1 in 2001. The comet last came to perihelion on May 28, 2015 and will next come to perihelion on February 1, 2022.
  The comet's nucleus, seen in the adjacent image, is particularly notable for being shaped like a bowling pin.
context_section_description: On September 21, 2001 the spacecraft Deep Space 1, which was launched to test new equipment in space, performed a flyby of Borrelly. It was steered toward the comet during the extended mission of the craft, and presented an unexpected bonus for the mission scientists. Despite the failure of a system that helped determine its orientation, Deep Space 1 managed to send back to Earth what were, at the time, the best images and other science data from a comet.
caption: The orbits of three periodic comets, 1P/Halley, 19P/Borrelly and 153P/Ikeya-Zhang, set against the orbits of the outer planets.