What are the facts on extrasolar bodies like exoplanets, what do we know as concrete facts?

Usually what we know is their mass, and their distance from the star. In the case of transiting planets, we can kinda guess their physical size as well. Harder with Doppler wobble, but with our understanding of how our own solar system works, we can make a good guess We find a lot of Hot Jupiters and a few Hot Saturns I think we have confirmed one count 'em one planet in the Goldilocks zone of its star (besides Earth) I THINK that Kepler 22b is the only one we have confirmed, but that Kepler scope is finding those things all the time.

I bet if you ask this again in three years, the answer will have gone up by dozens You have the right idea though. If the planet can have liquid water, it probably DOES have life. Liquid water is pretty much the whole show.

All the other stuff is a gimme. Its everywhere The universe is teeming with life. This Galaxy probably has hundreds, maybe even thousands of life bearing star systems.

There is a very limited amount of knowledge we know about extrasolar planets. None of it is enough to conclusively determine habitability. 1.

Its mass (technically only a lower bound for its mass can be known...it could be 10 times as massive and we'd never know) 2. Its orbital geometry and kinematics around its parent star 3. The properties of its parent star (temperature, mass, luminosity, physical size) 4.

Its radius, if we are VERY LUCKY to observe it transit its parent star 5. Its atmospheric composition, if we are EVEN LUCKIER to see it transit its parent star (usually only possible to do this for gas giants thus far) From this data (items 2 & 3), you can calculate a bulk temperature estimate for the planet's surface. This is where these planets get the hype of being in the "habitable zone", is if this temperature estimate yields values within the range of liquid water's possibility.

YET, this still isn't enough information to even conclude liquid water existing on the surface, because you need to know if the surface atmospheric pressure is enough to prevent liquid water from cavitating away as water vapor.

I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.