On 12/12/2017 10:31 AM, David Spain wrote:
On Thursday Dec. 14th NASA plans to announce the latest exo-planet
survey results using the Kepler Telescope.

The new wrinkle here is that Google machine learning AI was employed to
help with these newest discoveries.

It will be interesting to see if we not only get new planets in the
"Goldilocks Zone" but also of proper mass density for gravity close to
1g. In the past some of the most promising planet candidates have had
proposed gravity of up to 2g. All other things being equal, I suppose it
would be like living on Superman's home world of Krypton!*


Can anyone comment on how NASA came up with gravity estimates for past
exo-planet discoveries? It's not just mass that matters but density.

I suppose it's possible to estimate mass if you have a good
approximation of the the home star's mass and the orbital period of the
planet, but how about density? Is that largely an assumption based on
what we seen in our own solar system, or is it something that can be
revealed via observation? I could see spectral black body emission as
one way to determine a planet's composition, but I would think that is
beyond Kepler's ability?

Dave