Monday, March 08, 2010
Here's a video created a few days ago on some of the recently discovered (announced in December) super-Earths around the Sun-like stars they orbit.
The most interesting part is certainly the comment on how their discovery means we're also capable of discovering similar planets in M dwarf (red dwarf) systems as well, because with a Sun-like star these close orbits make the planet phenomenally hot while one orbiting a red dwarf might be in its habitability zone.
As for whether we are the odd man out in the universe or whether odd planets like these are the norm, I think it's too early to tell. We will probably have to wait until we reach the point where we can discover other planets like and even smaller then our own, and then wait another five to ten years after that in order to obtain a fairly large sample of small extrasolar planets before we can determine just what makes up a 'normal' solar system in the Milky Way and what doesn't. At present we do have a rough calculation though - the tentative answer is that solar systems like ours make up about 15 percent of the total.
And note that (as the article states) even a relatively low number like 15 percent means that there are a few hundred million solar systems like ours in just our own galaxy. Then multiply that by a few hundred billion to get a rougher than rough estimate of the number of solar systems like ours in the universe.