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View Full Version : Nagging question about Phoebe



John Dlugosz
2004-Jun-10, 10:23 PM
Today's headlines on Cassini-Huygens:

<http://www.spacedaily.com/news/cassini-04q.html>
"Phoebe has a diameter of 220 kilometers (about 136.7 miles), which is equal to about one-fifteenth the diameter of Earth's moon."

<http://www.spacedaily.com/news/cassini-04p.html>
"Phoebe is a tiny moon, only 110 kilometers (68 miles) in diameter. Earth's moon is more than 30 times as wide. "

Hopefully the encounter will setting this once and for all. Assuming they are looking around the right planet...

óJohn

tlbs101
2004-Jun-11, 12:39 AM
Maybe the 2nd reference meant to say "radius" instead of "diameter".

That's a good "BA" catch, though! =D>

ToSeek
2004-Jun-11, 12:40 AM
A quick Google (http://www.google.com/search?q=phoebe+diameter&ie=UTF-8&oe=UTF-8) seems to indicate that the larger value is the correct one.

Ian R
2004-Jun-11, 01:32 AM
Looking good...

http://saturn.jpl.nasa.gov/multimedia/images/small-moons/images/PIA06063-br402.jpg

http://saturn.jpl.nasa.gov/index.cfm

Jpax2003
2004-Jun-11, 01:54 AM
<http://www.spacedaily.com/news/cassini-04q.html>
"Phoebe has a diameter of 220 kilometers (about 136.7 miles), which is equal to about one-fifteenth the diameter of Earth's moon."Correct.


<http://www.spacedaily.com/news/cassini-04p.html>
"Phoebe is a tiny moon, only 110 kilometers (68 miles) in diameter. Earth's moon is more than 30 times as wide. "Incorrect, or Bad logic. Luna is 30 times bigger than half of Phoebe... Huh? I'm not 31 years old, I've simply been 21 for 10 years!

According to Nine Planets Luna (http://www.nineplanets.org/luna.html) is 3476km and Phoebe (http://www.nineplanets.org/phoebe.html) is 220km, thus 15.8x (http://www.google.com/search?hl=en&lr=&ie=UTF-8&q=3476km+%2F+220km+%3D&btnG=Search) difference in disc diameters.