Pluto Timeline of Events

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Pluto

Pluto, formal designation 134340 Pluto, is the second-most-massive known dwarf planet in the Solar System and the tenth-most-massive body observed directly orbiting the Sun...

Timeline of Events

1735

7.11.1735

Mathematical calculations suggest that it is on this day that dwarf planet Pluto moved inside the orbit of Neptune for the last time before 1979.

1915

3.19.1915

Pluto is photographed for the first time but is not recognized as a planet.

1930

2.18.1930

While studying photographs taken in January, Clyde Tombaugh discovers Pluto.

3.13.1930

The news of the discovery of Pluto is telegraphed to the Harvard College Observatory.

5.1.1930

The dwarf planet Pluto is officially named.

1978

6.22.1978

Charon, a satellite of the dwarf planet Pluto, is discovered by American astronomer James Christy.

1979

2.7.1979

Pluto moves inside Neptune's orbit for the first time since either was discovered.

1983

4.25.1983

Pioneer 10 travels beyond Pluto's orbit.

2006

1.19.2006

The New Horizons probe is launched by NASA on the first mission to Pluto.

6.21.2006

Pluto's newly discovered moons are officially named Nix & Hydra.

8.24.2006

The International Astronomical Union (IAU) redefines the term "planet" such that Pluto is now considered a Dwarf Planet.

2007

2.28.2007

Jupiter flyby of the New Horizons Pluto-observer spacecraft.