Enlarge / Just one of ... 110 planets in the Solar System? (credit: NASA/JHUAPL/SwRI) It's no secret that Alan Stern and other scientists who led the New Horizons mission were extremely displeased by Pluto's demotion from planet status in 2006 during a general assembly of the International Astronomical Union. They felt the IAU decision undermined the scientific and public value of their dramatic flyby mission to the former ninth planet of the Solar System. But now the positively peeved Pluto people have a plan.