Last week while I was catching the news via the Wii, there was a piece about the Europeans discovering another bunch of exoplanets (bringing the total to 400+). What made me cringe was the term Super-Earths being used for worlds that are easily a dozen times larger than our planet. Currently, astronomers don’t have the means to spot planets as “small” as Earth. They tend to find bodies bearing similarities to the gas giants: Jupiter, Saturn, Neptune and Uranus. Hardly Earth-like in any capacity because they’re too hot/too cold and primarily composed of hydrogen gas. Methinks the ignorant and lazy media needs to be given a remedial Astronomy course so they’d stop using the erroneous term.
It’s very simple: if a planet is at least five to ten times the size of Earth (any multiple of 25,000 miles in circumference or 8000 miles across), it probably doesn’t have a breathable atmosphere. Other things a world this large would have to disqualify it as an Earth-anything: bone-crushing gravity and/or a poor surface density for walking on. So far, the only models we have to go on are here in our solar system which tells us that worlds with tangible surfaces are quite small: Mars, the Moon, other planets’ moons, Mercury and Venus. Outside of those, Super-Earths belong to the realm of fiction with poor understandings of Astronomy: Star Wars, Star Trek, Lost in Space and Firefly. Babylon 5 got it right often and Futurama is a comedy. I haven’t seen enough of the revised Battlestar Galactica to know.
Don’t get me wrong though. It’s exciting to know there are planets orbiting other stars. The exoplanets prove that many stars aren’t vacant of orbiting objects. If there are Jupiters and Neptunes, then there are Venuses, Mercuries and (knock on wood) Earths. Just don’t break out the champagne and take out a second mortgage on the extraterrestrial property until we have the technology to find ones with attributes closer to Earth. However, if I’m wrong and fiction was right about a habitable world being possible with “ridiculous” stats, I won’t deny being incorrect and may even apologize to the boring, overrated writer Joss Whedon.