[X] My Assistant

[Toymaker]

http://www.nature.com/nature/journal/v441/...ature04828.html
Over the past two years, the search for low-mass extrasolar planets has led to the detection of seven so-called 'hot Neptunes' or 'super-Earths' around Sun-like stars. These planets have masses 5–20 times larger than the Earth and are mainly found on close-in orbits with periods of 2–15 days. Here we report a system of three Neptune-mass planets with periods of 8.67, 31.6 and 197 days, orbiting the nearby star HD 69830. This star was already known to show an infrared excess possibly caused by an asteroid belt within 1 au (the Sun–Earth distance). Simulations show that the system is in a dynamically stable configuration. Theoretical calculations favour a mainly rocky composition for both inner planets, while the outer planet probably has a significant gaseous envelope surrounding its rocky/icy core; the outer planet orbits within the habitable zone of this star.

[ljk4-1]

While these planets themselves may not harbor life, I wonder about
any moons circling them?

The potential for tidally heated icy and temperate moons around exoplanets

Authors: Caleb A. Scharf

Comments: 28 pages, 8 Figures, AASTex, Accepted for publication in the Astrophysical Journal

http://arxiv.org/abs/astro-ph/0604413

[dvandorn]

While these planets themselves may not harbor life, I wonder about
any moons circling them?

Well, hmm... depending on the age of the planetary system, any such moon of a Neptune-mass planet within the habitable belt of a star would have to share certain properties with Earth (enough mass to hold on to an atmosphere, liquid water on the surface, a magnetic field to protect the planet from both the solar wind and the primary's radiation belts, etc.) such that life could develop.

As long as all of those conditions exist, I don't see why life couldn't develop on such moons.

Of course, the star-wiggle technique will likely never be able to identify Earth-sized moons of hot Jupiters or hot Neptunes (or even temperate versions of similarly-massed planets). So we'll need SIM and TPF to get even the first clue as to how many of those there might be out there.

-the other Doug