If you’re a Star Trek fan, then chances are you know about the planetary classification scheme that’s used to identify a planet so you know what to expect of the world before you get there. The solar systems devised were no doubt ahead of their time, however they were modeled largely after the only planetary model the creators had at the time – ours. Hence the reason why most of the rocky planets are nearer their star, while the jovians (large gas planets) were located further out.
Since then, astronomers, using such sci-fi classics as Star Trek as inspiration, have discovered over 1000 exoplanets orbiting dwarf stars of all sorts, and only within a small sector of our interstellar neighbourhood. It has even warranted a planetary classification system; fixed, of course, to represent the true distribution of exoplanets in the galaxy.
Comparing solar systems:
To the right we see our Solar System, click it to enlarge. There are eight planets in our Solar System, which is still more than what any other known solar system has to this date. And notice in the diagram at the top right where the small, rocky bodies are located, compared to the large, jovians.
Keep that in mind…
Now look at this schematic of all the exoplanets discovered not using the Kepler Space Telescope, and compare this to that of our Solar System. Notice where most of the exoplanets fall – Hot Superterrans, Hot Neptunians, Hot Jovians, Warm Jovians, and Cold Jovians. Except for the Cold Jovians (we have two of our own), these groups contain planets that are, in some cases, completely alien to the planets we’re familiar with.
This planetary distribution found by the Kepler telescope shows again a spread – this time, Hot Subterrans, Hot terrans, Hot Superterrans, Hot Neptunians, and Hot Jovians. Except for the Hot Terrans (Venus goes into this category), these planetary groups are also quite different to what we’re used to seeing.
Below you see the most common solar system layouts we’ve come across so far (generally-speaking). Notice how none of the above looks like our own. So why are there so many hot worlds? Well, we’re working on it…These exoplanetary systems really are alien in most cases, and it’s even forced astronomers to reconsider the model of solar system formation that seemed so accurate before we starting finding exoplanets left, right, and center.
It’s even beginning to look as if our Solar System is the mutant of the galaxy, since it, unlike the vast majority of exoplanetary systems, doesn’t seem to show much signs of the inward migration so prevalent in other star systems. It kind-of begins to make Star Trek look unimaginative, doesn’t it?