The Star Trek universe is the only place I know of where one will hear references to an "M Class planet." OK. What is an "M Class planet," anyway? Any Trekkie will tell you it's an Earth type planet. OK. But where does the term come from? NASA? Astronomers? Mt. Palomar Observatory? The late great Carl Sagan? Nope. Look it up. It exists only in Star Trek and the minds of Star Trek fans. In the real universe there is no such thing as an "M Class planet." It was made up for Star Trek back in the 60's when writers for the TV show wanted to have some scientific sounding shorthand to refer to different types of planets but didn't have a clue how real life astronomers and scientists talked about real life planets (of, course, to be fair, Earth WAS the only Earth type planet we knew of back then). Check it out here: http://en.wikipedia.org/wiki/M_class_planet (there are references), and here: http://en.memory-alpha.org/wiki/Class_M. In the Star Trek universe there exists a whole long range of planets designated by letters, A-Z. It is one way in which the Star Trek universe is organized.
Now, that's OK. You create your universe. You create the categories in that universe. You create the terminology. You decide the norms. You create your own frames of reference. I'm all for it. Do it as much as you want and more power to you. If you want to see an intentional major effort to do this among a number of science fiction creative types, just check out Orion's Arm here: http://www.orionsarm.com/xcms.php?r=oa-intro. They have their own classification scheme for planets, and I haven't seen an "M Class planet" there yet. In fact, they have 18 (yes, eighteen) different classifications for Earth type worlds, not to mention all the others in their user-created universe. (See: http://www.orionsarm.com/eg-article/491c78b89879b)
And this is OK. I like it. I wouldn't want to imitate it, but I like it.
I suppose one of the points I'm getting at, perhaps a soapbox for me, is the extent to which Star Trek and Star Wars have influenced the thinking of the American science fiction community. I like Star Trek, TOS and the new movies since 2009. I like Star Wars. But, please, let's not treat Star Trek and Star Wars as if they are the end all of science fiction. (Indeed, it could be argued that they aren't even science fiction at all, but a form of "science fantasy," if that matters, and to some people out there, it does. See here: http://scifi.about.com/od/starwarsglossaryandfaq/a/Star-Wars-Faq-Is-Star-Wars-Sci-Fi-Or-Fantasy.htm, here: http://forum.gateworld.net/threads/10755-Star-Trek-Science-Fiction-or-Fantasy, and here: http://io9.com/damon-lindelof-star-trek-is-hard-science-fiction-not-483030807.)
But let's not get distracted. This is not about whether or not one or another space tale is science fiction or fantasy. The point really is that there are other ways to be creative. A whole universe of ways. Be yourself. Do your own thing. Create your own universe. Be independent. To quote a character in one of my (no, not published yet) stories, "The thing to do is to strike out on one's own, irregardless. Take off! Be free! Independent! Head for the stars! Life is waiting, you see."
And so we come back to world building. Star system building. Universe building. Classify your worlds anyway you want, but strive to be creative. Independent. BTW, another example of planet classification may be found here: http://home.arcor.de/christianlenz/planet_classes.html
Finally, if any other indie creators out there are working to build their own science fiction worlds, I'd like to hear about it.
Oh, yeah, needless to say, there are no "M Class planets" in the Terra Arcadian universe. But there are plenty of Terran Class worlds nonetheless.
pax, J Allen W
