Vote on Pluto: Should it be called a planet?

Cast your vote on Pluto at HighlightsKids.

February of 2010 marked the 80th anniversary of the discovery of Pluto by American astronomer Clyde Tombaugh.

Ken Croswell: I would just like everyone to realize that Pluto is the 10th largest object that goes around the sun, and I think it deserves a little more respect than it’s received from certain Pluto-phobic astronomers.

Astronomer and author Ken Croswell told us that you can vote – in February of 2010 – on whether Pluto should be a planet. The magazine Highlights for Children is hosting the vote at HighlightsKids.com. In 2006, a vote of about 400 astronomers with the International Astronomical Union, or IAU, demoted Pluto from full planet to dwarf planet status. The new IAU planet definition mentions orbits.

Ken Croswell: Pluto is not a planet because Pluto crosses the orbit of Neptune, which is a no-no.

But Croswell said distant solar systems are now known with planets crossing each other’s orbits. He said other astronomers want to define planet as round, like Earth, due to self-gravity.

Ken Croswell: It would confer planet-hood not just on Pluto but on so many other things too, probably dozens – if not hundreds – of other objects in the solar system.

Croswell believes we should define a planet simply – as something that goes around the sun and has the diameter of Pluto or more. Cast your vote on Pluto at HighlightsKids.

Ken Croswell: Now, my own opinion as to what I think a planet is, I have a different definition, a much simpler definition of planet. I think we should just define a planet as something that goes around the sun and has the diameter of Pluto or more. By that definition, Pluto is a planet, and the solar system has 10 planets all together, Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto, and Eris. Discovered in 2005, Eris is farthest thing ever seen in our solar system. It’s nine billion miles from the Sun, three times farther than Pluto, almost 100 times farther from the sun than the Earth is, and Eris would be the 10th planet in our solar system.