https://www.washingtonpost.com/news/speaking-of-science/wp/2017/10/21/a-newly-discovered-moon-tunnel-could-be-the-perfect-place-for-a-colony-scientists-say/
origin - http://www.pipiscrew.com/?p=10589 a-newly-discovered-moon-tunnel-could-be-the-perfect-place-for-a-colony