This is especially interesting considering what 90% of my portfolio consists of today.
As usual — I really had no idea what the book was about, but probably decent as Hartmann is a well-respected sciFi author. The concept was just a literal translation of the title. Mars is half underground in Martian soil.
Interesting note: The.surface images of Mars here are from Viking. Because in 1996… no other probe had imaged the Martian surface other than Viking 1 and 2. The return to Mars after 20 years didn’t happen until 1997 with the Sojourner Rover.