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Name: Haylee
Status: other
Grade: other
Location: NV
Country: N/A
Date: N/A

Why is Pluto no longer a planet?

Dear Haylee,

Yes, Haylee, there is a planet named Pluto. However, a group of people at the "International Astronomical Union" voted to define the solar system differently from what it was. Now there are 8 regular planets-- Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. There is now a new class of worlds called "dwarf planets". That includes our friend Pluto, and -- here is the good news-- it also includes the asteroid Ceres, the biggest asteroid.

planet?" Lots of them say no, but I disagree. Did you know that our Sun is a dwarf star? And it is of course a star. So I am going to keep on calling Pluto a dwarf planet, until someone tells me I cannot.

Haylee, with me, your question is very personal. I knew Clyde Tombaugh, the man who found Pluto, very well. In fact I wrote his biography Clyde Tombaugh: Discoverer of Planet Pluto. He is no longer living but his wife and family is. So I thank you for asking your question.


David H. Levy

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