Meet Pluto’s Hidden Moons

While Pluto may have been demoted to dwarf planet status, it seems that the little celestial body has plenty more secrets to share. A fifth moon was found during a July 7th infrared observation, using the Hubble Space Telescope‘s Wide Field Camera 3. Temporarily known as S/2012 (134340) 1, the latest moon was detected in nine separate sets of images taken June 26, 27, 29, and July 7 and 9.

The discovery team had been scouring the Plutonian system looking for potential collision threats to the NASA New Horizon spacecraft, expected to fly by in 2015. New Horizon, launched in 2006, will be traveling an expected 30,000 miles per hour by the time that it reaches the dwarf planet and would be severely damaged or destroyed by a particle as small as a BB-shot, so you can imagine the importance of determining everything orbiting within the Pluto system.

The official HubbleSite piece quotes Alan Stern, of the Southwest Research Institute in Boulder, CO, the mission’s principal investigator: “The inventory of the Pluto system we’re taking now with Hubble will help the New Horizon team design a safer trajectory for the spacecraft.”

Pluto’s largest moon, Charon, was discovered in 1978 by astronomers using the United States Naval Observatory in Washington, DC. Just before Pluto’s reclassification as a dwarf planet in 2006, two more moons were found, Nix and Hydra. Just last year, the 4th moon was found after closer examination of Hubble data. This 5th moon is just another piece to the puzzle in explaining just what happened to Pluto during its long history. The current theory is that there was a massive collision between Pluto and another Kuiper belt object, causing Pluto to shatter into many pieces and knocking the dwarf planet out of its former obit.

“The discovery of so many small moons indirectly tells us that there must be lots of small particles lurking unseen in the Pluto system,” Harold Weaver of the Johns Hopkins University Applied Physics Laboratory in Laurel, MD explains in the HubbleSite article.

After New Horizon passes through the Plutonian system, researchers are planning to rely on additional infrared data provided by the James Webb Space telescope, to measure surface chemistry of Pluto, its moons and other Kuiper belt objects. These measurements will allow researchers to figure out which objects originally were parts of a larger planet or object.