I’m no astroseismologist but I feel like I’ve heard of sensors like this being on satellites like to investigate glaciers etc. though maybe 10km of rock isn’t so easily penetrated.
They did also say in the article that the rover could only measure straight down from its position, so maybe not all of the water is so deep.
Maybe gold or something
Hang on guys, maybe it was an official rape.
It looks like you can push the button without lifting the tiny computer.