Massive lava tubes under the surface of the Moon and Mars could be prime real estate for future offworld habitats. "With heights that dwarf Dubai's Burj Khalifa, the world's tallest building, and 'skylights' as big as football fields," the formations could contain small cities protected from solar radiation, reports LiveScience. According to a new study [&]

https://boingboing.net/2020/08/18/lunar-and-martian-tunnels-coul.html