It's Time for the IAU to Define a Moon
OK IAU -- You took it upon youself to give us a definition for "planet" and for that we thank you. In the last month, the 60th "moon" has been discovered orbiting Saturn. Question: When does a moon stop being a moon and start being just another space rock orbiting a planet? I think it's time to get your creative juices flowing and come up with a new definition for "moon."
Comments:
For me if it ain't roughly spherical under its own gravity, it ain't a moon. That would leave out Phobos and Deimos, but what the heck.<br><br>If it has a substantial atmosphere, it is more like a planet, despite orbit around another planet. There goes Titan. But then Mercury is what?<br><br>These are all popular designations anyhow- what is the point anymore for professional purposes- maybe they just need a string of feature designations (like 134873) each digit of which would pigeonhole a particular aspect (for instance a rogue planet might be 1, a stellar planet 2, and a planet (Titan) orbiting a larger nonstellar body 3, and so forth). I'm sure we could get most relevant information into something as long as a phone number. And this could cover all material bodies.<br><br>Most bodies in space are likely to be electrically uncharged- they'd get the 1-800- designation... <img class='' src='http://new.astromart.com/astromart/javascripts/sceditor/emoticons/grin.png' alt='grin' title='grin'/> <br><br>Jess Tauber<br><br>
You mean sort of a dewey decimal system of the universe? <img class='' src='http://new.astromart.com/astromart/javascripts/sceditor/emoticons/grin.png' alt='grin' title='grin'/> <br><br>I think it's strange how the general public gets so worked up about topics of astronomy that have the least scientific value. My biggest fear is that people reading the news will think that astronomers spend all of their time arguing about what objects should be called.
If we let the IAU open this topic, watch out! Are we really ready to rewrite all the nursery rhymes? Maybe we don't really have a moon? Maybe we have a co-planet? The cow jumped over the co-planet...<br><br>They should leave well enough alone.
I agree about the definition but I hope that it has more meaning than apparently their definition for planet. I pray that whatever criteria they select will be universally and judiciously applied.
