"The newly discovered features, however, were detected more than 35 kilometers beneath the planet’s surface."
"As a result, 16 mysterious polygons were spotted below a depth of 35 meters, meaning they were likely formed billions of years in the planet’s past."
I suspect it is only meters, as the limits of ground penetrating radar carried on-board the rover, likely can't achieve the 35 kilometer depth.
Really! 35 km.
I was thinking , “That’s not a Chinese probe! They’re drilling for oil!”