New Horizons mission to Pluto: initial results

Article By:

Person, Michael J. Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts.

Last reviewed:2016

DOI:https://doi.org/10.1036/1097-8542.YB150707

When it was launched on January 19, 2006, the New Horizons spacecraft began the final phases of a greater-than-20-year quest to send a discovery craft to distant Pluto. More than that, it was about to complete the first full survey of our solar system. Starting with the first flyby of Venus by the Mariner 2 spacecraft in 1962, discovery missions had been sent to every other planet in the solar system, with the outer, more distant planets coming later, culminating with Voyager 2's flyby of Neptune in 1989. However, the Voyager probes were unable to travel to our ninth planet, Pluto, as the orbit required would have been forced to shortchange the Saturnian system, considered to be a higher-priority target. Throughout the years following Voyager, scientists lobbied to get a spacecraft to our final planetary neighbor, but it was not until 2006 that this last planetary discovery mission was ready to close out the initial inventory of the solar system. Many found it highly ironic that the planet Pluto's status was changed to that of a dwarf planet by the International Astronomical Union seven months after the historic launch. Planet or not, however, New Horizons was already on the way to the Pluto system. See also: Planet; Solar system; Space probe

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