Scientists first discovered Pluto. It took them this long because it was so far away. They had guessed something was there because of Neptune’s orbit.
Pluto's moon Charon
In 1978 James Christy observed that there was a satellite that went around Pluto every 6 days and named that satellite Charon.
Pluto and Charon go through eclipses
1985 - 1990
Pluto and Charon went through a series of eclipses and using that information in 1985-1990 they were able to figure out features of Pluto and Charon.
Nix and Hydra
We have found other moons of Pluto using the Space Hubble Telescope. We found the moons Nix and Hydra in 2005.
Category Dwarf Planets
Astronomists first made the category called dwarf planets. Dwarf planets are large enough to become a sphere but not large enough to clear its space in the solar system. This is when they put Pluto into that category.
Pluto is not a Planet
Astronomists decided Pluto was not a planet because it was not big enough and its orbit was different from all the other planets.
We have found other moons of Pluto using the Space Hubble Telescope. We found Kerberos in 2011
We have found other moons of Pluto using the Space Hubble Telescope. We found Styx in 2012.
The New Horizons probe became the first spacecraft that visited Pluto and sent back the first clear pictures of Pluto’s surface. Pluto was icy with mountains and plains and even has a nitrogen atmosphere.