Photos of the Sun

New Horizons on Pluto. Uranus, Neptune and Pluto

New Horizons on Pluto. Uranus, Neptune and Pluto

Until 2005 it was believed that the dwarf planet Pluto had only one satellite, Charon. On May 15 of that year, astronomers working with the Hubble Space Telescope discovered two new moons on Pluto. They were designated with the provisional names S / 2005 P1 and S / 2005 P 2.

Subsequently, the International Astronomical Union officially renamed Pluto's satellites with the names of Nix and Hydra. His initials, NH, pay homage to the New Horizons space probe, which took off for Pluto in 2006.

Hydra is Pluto's outer moon, while Nix is ​​his inner moon. Both orbit the planet at a distance two and three times greater than the orbit of Charon. Nix is ​​48,700 kilometers away and Hydra 64,800 kilometers from the barycenter of the system. They have almost circular orbits, and both satellites orbit in the same plane as Charon.

Both Hydra and Nix appear to have a diameter of between 100 and 150 kilometers. Because of the brightness that Hydra sometimes emits, it is likely to have some dimensions larger than the Nix satellite.

It is currently considered that all Pluto satellites were formed after a large collision, a process very similar to what is believed to have happened with respect to our Moon. Previously it was thought that they were objects of the Kuiper Belt that had been captured by Pluto's gravity.

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Album: Photos of the Solar System Gallery: Uranus, Neptune and Pluto