There are bacteria today that can live without sunlight. Some species of cyanobacteria are highly resistant to ultraviolet radiation. The only thing absolutely essential for bacteria to live, grow, and multiply is liquid water. We are confident that the early Earth had plenty of water. Scientists believe that concentration of water in the earliest atmosphere for which they have data, over four billion years ago, was far higher than it is today.
Bacteria have the ability to colonize an unfriendly planet like the Hadean Earth.
Not just had the ability but have the ability. These are not make believe stories. Bacteria at the South Pole. A team of explorers including astrobiologist Richard Hoover and astronauts Jim Lovell and Owen Garriott traveled to Antarctica in January 2000 to search for extreme-loving microbes. Microbiologists have recovered a cunning new microbe from the scalding fluid ejected during a submarine eruption.