Bad Astronomy and Universe Today Forum - View Single Post - Interesting extrasolar planet discoveries

Sporally · #**301** (**permalink**) 11-October-2008, 01:21 PM

And here are some data about the sizes of each planet in Jupiter masses:

Gliese 876c: 0.56
HD 92788b: 3.86
HD 16175b: 4.5
HD 20367b: 1.07
HD 142415b: 1.62
HD 142b: 1
HD 108874b: 1.36 (that solar system also features a Jupiter sized planet 2.5 times as far away from the sun - maybe helping in the defence of a possible moon with life)
HD 150706b: 1
HD 190228b: 4.99

So from the data above i would say when we get those planets with a size like:

HD 92788b
HD 16175b
HD 190228b

... as possible planets with a Earth-sized moon around them.

Is the calculation of how big a moon typically would be if you for instance double the size of the planet? I mean, taking a planet with 2 Jupiter-masses, would that mean that it is likely we would get a 2 Ganymedes-masses moon around that planet or isn't it a linear calculation?

BTW: Would it be easier or harder to find a Earth-sized moon around a planet than a Earth-sized planet around a star if we would search just as many of each type? I'm not talking about in which situation there are most Earth-sized planets/moons, but what future telescopes like Kepler would find easier finding.