Aug 23, 2006
02:24 PM
The Life

Is Pluto-Charon a double planet?

By admin
If tomorrow's vote goes well, there may be something new under the sun.

Or over the sun.

Or somewhere around the sun. Don't confuse me.

From the International Astronomical Union site:

Q: Why is Pluto-Charon a "double planet" and not a "planet with a satellite"?
A: Both Pluto and Charon each are large enough (massive enough) to be spherical. Both bodies independently satisfy the definition of "planet." The reason they are called a "double planet" is that their common centre of gravity is a point that is located in free space outside the surface of Pluto. Because both conditions are met: each body is "planet-like" and each body orbits around a point in free space that is not inside one of them, the system qualifies to be called a "double planet."

[Finally, here's a fascinating Pluto-Charon orbit simulation, courtesy of George Greenstein and his students at Amherst College.]

Comments to this website are moderated by staff. While all comments are welcome, we encourage all to be polite and please do use this system for advertising or business promotions. Any complaint towards a business or service should be directed directly to that business and not posted here. If anyone has a complaint that a comment is defamatory, please contact me at tmay@palmspringslife.com and I will take appropriate action promptly. Thank You

Add your comment:
Verification Question. (This is so we know you are a human and not a spam robot.)

What is 2 + 1 ?