Back when Star Wars was new – and even when the new trilogy was new -, a planet orbiting more than one star was nothing more than speculation. (Though back when SW was new, even a planet orbiting another star was little more than speculation.)
I’m excited to see that the Kepler team are busy turning it into solid reality. They now have not one, not even two, but three planets that they found around binary stars (the first was described a few months back [Doyle et al., 2011]; the other two are just online [Welsh et al., 2012]). None of them are particularly Tatooine-like, alas, since all are gas giants, but given how hard small planets are to find, we can be fairly confident that we’ve just overlooked them so far.
All three planets orbit in the same plane in which their stars orbit each other, indicating that the whole system formed from the same rotating disc of space debris. Based on the number of star pairs they’ve looked at so far and the chance of observing planetary transits in binary systems like Kepler-16, 34 and 35, Welsh et al. estimate that millions of similar systems could be hiding in the Milky Way alone.
To top it off, another new Nature paper (Cassan et al., 2012) reports that in fact, most sun-like stars in the galaxy are likely to have planets.
A truly astronomical number of strange new worlds are out there. How many of them could harbour life?
(Can you hear my inner geek squealing with joy? :D)
Cassan A et al. (2012) One or more bound planet per Milky Way star from microlensing observations. Nature 481:167-169
Doyle LR et al. (2011) Kepler-16: A transiting circumbinary planet. Science 333:1602-1606
Welsh WF et al. (2012) Transiting circumbinary planets Kepler-34 b and Kepler-35 b. Nature advance online publication, 11 January 2012, doi:10.1038/nature10768