I don't quite see how this find sheds new information on possibility of life on Mars. I though the greatest challenges to life on Mars were large temperature va

I don't quite see how this find sheds new information on possibility of life on Mars. I though the greatest challenges to life on Mars were large temperature variations and lack of liquid water. It is already known that life could thrive in an oxygen-free environment, after all it had to start on Earth some-how.