A more interesting paper is Life Before Earth, https://arxiv.org/abs/1304.3381, analyzing biological complexity and projecting into the past for an origin of 9.7 billion years ago.
That's one hell of a refutation.
> In particular, photosynthesis or chemosynthesis is needed to be independent from organic resources.
It's weird because the current estimation is that photosynthesis appeared like 1000 millions years after the fist cell. So if this article were correct and the initial cells population came from space, they probably would no have photosynthesis.
(With 1 molecule per cm^3, you get like 10 more bases in locations for random chains.)
It's actually more complicated, because shallow part of the sea or fumes near ocean rigs may have more concentration, and 1 molecule per cubic meter is a very low concentration. Anyway, extrapolating to 1 base is too extreme.
Also, they had a nice fit for DNA based life, and they discuss the RNA World hypothesis, but it's not clear that the fit for DNA can be extrapolated to the RNA or whatever was used before.
(There is a recent paper that propose a mix of RNA and DNA instead of a pure RNA word. We still don't know.)