Pluto's known moons. Source
New evidence says that Pluto, the not-planet (sorry), might have as many as 10 tiny moons orbiting around it. Ever since Pluto's discovery in 1930 scientists have been discovering more and more large objects orbiting around it. The most recent moon (circled in this picture) P5 was discovered last year, but these potential moons pose a threat to the New Horizons mission which is scheduled to perform a close flyby to Pluto in 2015.
To read more, check out this article.