In the search for habitable planets, we thought we knew what to look for: foreign solar systems resembling our own. We were wrong.
Our home system, it turns out, is a place of exceptional order, with its neat arrangement of small rocky worlds close to the sun, and far-flung gas giants. When we stare beyond its confines, we come across nothing else quite like it. Instead, we consistently find systems where gas giants and rocky planets are mixed together higgledy-piggledy. If we assume that such an arrangement is the upshot of a long history of instability, it severely limits the time that life would have had to get started in most of the cosmos.
But we are now beginning to question a number of long-held assumptions about what makes a planetary system amenable to life. In particular, the role of gas giants like our very own Jupiter are under scrutiny. Maybe life can find a foothold in systems where these giants are not quite so placid after all.
To read more, click here.