I’ve always assumed that the characteristics of our solar system would prove to be typical of most solar systems we would find throughout the galaxy.
However, that doesn’t appear to be the case at all: As of this month, we’ve discovered 884 planets, 692 planetary systems, 132 of them with more than one planet and, strange to tell, almost none of them look like us.
“So our solar system is, in some sense, a bit of a freak and not the most typical kind of system that Nature cooks up.”
Steve Vogt, astronomer, University of California
The newest explanation is that new planets don’t stay put. They move. A gassy planet will form on the far side of the frost line, orbit for a while, and then gradually move inward, pulled in closer by the star. It stops only when the sun pushes back
“It really is something that I find deeply weird. What does it all mean? I don’t know. I am certain that this single-minded emphasis on planets-in-habitable-zones is making people forget that there is still a lot of weird stuff happening out there and that we still don’t even understand the basics of how we ourselves got here.”
Mike Brown, astronomer, Caltech