An exosolar guide of planets by size vs density and theoretical composition.

What with Pluto being demoted and exosolar astronomy going gang busters, a solar system with more planets than our own was bound to turn up sooner or later. New data from a near twin of our sun 130 light-years away has come sooner:

(BadAstronomy) — The new analysis looks at the old data in a different way, examining it using different statistical methods. Not only are the six planets seen in the new results, but the seventh is confirmed, as well as finding two additional planets in the data. If this result pans out, that means HD 10180 has nine planets, more than our solar system does! The three additional planets have masses of 1.3, 1.9, and 5.1 times that of Earth, and orbit the star with periods (think of that as the planets’ years) of 1.2, 10, and 68 days, respectively.

Those are also among the lowest mass exoplanets ever detected, or suspected anyway. But they’re no place for earth-like extremophile microbes, let alone the larger stuff. Two of them are closer to their sun than Mercury is to ours. Even with no atmosphere to trap heat like Venus, they’d be roasting along at a blistering 1000°F or so.