A robotic research probe is exploring a liquid methane sea on Saturn's moon Titan. The probe descends vertically from a depth of 4.20 m4.20\text{ m}4.20 m to a depth of 28.60 m28.60\text{ m}28.60 m below the surface of the sea.
Given:
Explain why the fluid pressure on the probe increases as it descends deeper.
Calculate the increase in pressure on the probe. State the unit.