The discussion centers on the consistent temperature found underground regardless of surface conditions, with a focus on the potential temperatures at depths of around 20 feet on planets like Titan and Venus. It highlights that the average surface temperature of Venus is approximately 461°C, suggesting that temperatures at that depth would be similarly extreme if soils are present. For Titan, the presence of water ice and methane ice indicates much colder temperatures, likely around -180°C, influenced by the mineralogy and pressure at that depth. The conversation also touches on the possibility of liquid water existing underground in extreme environments, as seen on Earth where water can be found below the surface even in desert regions. The ongoing exploration of Mars by NASA is mentioned as part of the search for subsurface water, reinforcing the idea that extreme surface conditions do not necessarily preclude the presence of liquid water underground.
