[Recently, a planet around Proxima Centauri has been found](http://news.nationalgeographic.com/2016/08/earth-mass-planet-proxima-centauri-habitable-space-science/).
It is in the habitable zone, in the sense that if the planet was a black body, it would have a surface temperature of −39° Celsius. The planet is very close to its star, which has a number of implications:

* Radiation is very strong (additionally, Proxima Centauri is a [flare star](https://en.wikipedia.org/wiki/Flare_star)), and probably has stripped the planet of its atmosphere.
* The planet is probably in a tidal lock, with one side facing the star constantly and the other pointing into cold space.

I'm therefore assuming that the planet has no atmosphere, but can support liquid water somewhere on the dawn area, where the star shines at a steep angle.

*What life forms with the greatest similarity to life on earth are possible on this planet? In what points do they have to differ from earth life?*