In addition, other solvents might host life. "Saturn's moon Titan has liquid methane and ethane." Seager said.
Second, life needs energy. Without energy, virtually nothing would happen.
The most obvious source of energy is a planet or moon's host star, as is the case on Earth, where sunlight drives photosynthesis in plants. The nutrients created by photosynthesis in turn are what the bulk of life on Earth directly or indirectly relies on for fuel. (50 Amazing Facts About Earth)
Still, countless organisms on Earth subsist on other sources of energy as well, such as the chemicals from deep water vents. There may be no shortage of energy sources for life to live off.
Scientists have argued that habitable worlds need stars that can live at least several billion years, long enough for life to evolve, as was the case on Earth.
Some stars only live a few million years before dying. Still, "life might originate very fast, so age is not that important," astrobiologist Jim Kasting at Pennsylvania State University told OurAmazingPlanet.