Photo credit: NASA
We all learned in school that there are 9 planets orbiting our sun, right? Many of us know that Pluto has been degraded from a planet into a dwarf planet. But how many do know that there are more than 9 objects (including Pluto) orbiting our sun? Meet the Solar System's Dwarf Planets!
Pluto was degraded into a dwarf planet on August 24, 2006 by the International Astronomical Union (IAU). That was due to the discovery of multiple large bodies orbiting even farther from the sun than distant Pluto. These are our newly found neighbors:
Eris: Artist's rendering of Eris, announced in July 2005 by Mike Brown of Caltech. It is more massive than Pluto. The sun is in the background. CREDIT: NASA/JPL/Caltech
Haumea: Artist's concept of the dwarf planet Haumea and its two satellites (Hi’iaka and Namaka). CREDIT: SINC/José Antonio Peñas
Makemake: An artist's illustration of Makemake, a dwarf planet out beyond the orbit of Neptune that also qualifies as a plutoid. CREDIT: IAU/M. Kornmesser
Ceres: This Hubble Space Telescope image shows Ceres, the most massive object in the asteroid belt, a region between Mars and Jupiter. Hubble images are helping astronomers plan for the Dawn spacecraft's visit to Ceres in 2015. CREDIT: NASA, ESA, J. Parker (Southwest Research Institute), L. McFadden (University of Maryland)
There are more info about these objects, as well as full-sized photos in this link (space.com)