July 12, 2012
Today, astronomers using the Hubble Space Telescope announced that they have discovered Pluto’s fifth moon. Scientists have been looking closely at the space around Pluto because they are preparing for the 2015 Pluto flyby of NASA’s New Horizons spacecraft. New Horizons is going to give us our closest look yet at the dwarf planet, so NASA engineers want to map as many potential crash hazards as they can and design the safest possible course for the probe.
For the moment, the new moon is simply called S/2012 (134340) 1, or "P5" for short. Eventually, the International Astronomical Union will give names to P5 and P4, the fourth moon that was discovered late last year, and they will probably be names from Greek mythology. Pluto’s first three moons were named after mythological characters associated with the underworld. Greeks believed Charon was the ferryman who carried souls across the river to the underworld. Hydra was the serpentine monster that guarded the gates of the underworld, and Nix is named after the Greek goddess of the night.
The team is waiting awhile before naming P4 and P5, in case a P6 comes along. One thing for sure is that we’re going to learn a lot more about Pluto and the objects orbiting it in the next three years.
The timing of this discovery is good for one of my new eBooks. We are updating SPACE WORDS: A DICTIONARY for publication as an eBook, and my editor just changed the Pluto entry to state that it has five moons. Surely this will be the most up-to-date reference out there when it is published in late July!
Photo: M. Showalter / SETI Institute / NASA / ESA
Posted by: Seymour Simon
