Tiny Pluto has a lot of followers. Being relegated to being a ‘dwarf planet’ from being a ‘planet’ has apparently not hurt Pluto’s chances of capturing a moon. It already has four moons, all of them tiny. Now, a fifth one has been discovered by the Hubble Space Telescope.
We covered the news of the discovery of the fourth moon of Pluto here and it was called P4. This new one has been provisionally christened S/2012(134340)1, but it already has gained the title ‘P5’. The other moons of Pluto are Charon (biggest), Nix and Hydra, apart from P4.
The announcement of the discovery came through Twitter when principal investigator in NASA’s New Horizons spacecraft Alan Stern said:
Just announced: Pluto has some company – We’ve discovered a 5th moon using the Hubble Space Telescope.
Oh, and the New Horizons spacecraft project plans to fly by Pluto in a bid to discover new horizons and study the dwarf planet. The launch is scheduled in 2015.
Difficult to see
Pluto and its moons are notoriously difficult to see. They tend to be blips of light, in the midst of a background made up of blips of light. The only difference is that the moons of Pluto go around Pluto, rather than the Sun, which the blips of light in the background do. The moons are quite small. Charon is the biggest, measuring about 1000 km across. The scale falls sharply with Nix and Hydra measuring about 80 km or lesser. P4 is about 30 km across.
It turns out that P5 is even smaller. It’s about 20 km across, but at places it measures less than 10 km, indicating that it is highly irregular. It was Hubble’s Wide Field Camera 3 which caught the 5th moon.
Many believe that Pluto might ‘capture’ planetary debris from their irregular orbits around the Sun and make them its moons.