"but astronomers have found the first potentially habitable planet, as in it has the possibility of liquid water on its surface and an atmosphere." There is already one found called planet Earth..
The earth is habitable, not
potentially habitable
For sure it must have liquid water and an atmosphere, just like all the rocky planets on our solar System, the question is , does it possess oceans? What makes our planet rather unique is not liquid water but the presence of oceans
Any significant amount of surface water will lead to oceans, no large impacts are required. Mars appears to have had a very large ocean, early in its history. Europa also appears to have oceans; in fact, it may be 100% ocean under its frozen surface.
Whether oceans are required for life to form is a completely different question. Unrooted phylogentic trees suggest that the last universal common ancestor (LUCA) was likely a hypperthermophile - organisms which live in hot-springs, around sub-sea vents, and deep within the crust of the earth itself. Assuming that this indicates the conditions that led to the evolution of the LUCA, an ocean (where abiotic chemicals would be quite dilute) would be one of the last places we'd expect to see life forming. Rather, we'd expect it to occur in hot springs, or perhaps within the crust of the earth itself - i.e. places where appropriate temps and high concentrations of abiotic materials will be maintained.
Bryan
The chances of that happening to a different planet to the same way it happened to Earth are rather slim-to-one.. [/quote]
