The different planets of the solar system, this video focus' on Pluto.
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Male Speaker: Because of the fact that Pluto was considered as a planet for most of the 20th century, we've decided to throw it an honorable mention. In 2006, the international astronomical union officially defined what a planet is leaving Pluto out. The new definition designated Pluto as a dwarf planet. In recent years, discoveries have been made specifically of Aries, which was larger than Pluto. This ignited at a bay on what made a planet officially a planet. It is extremely difficult to study Pluto because of its extremely small sizes and the fact that the so far from earth. Pluto's diameter is only 19% of the size of the earth. NASA's new horizon was launched in 2006 and is expected to reach its closest point to Pluto in 2015. Pluto has three natural satellites, one was discovered at 1978 or the other two were not discovered until 2005.