Europa, one of Jupiter’s largest moons, has a subsurface ocean beneath its icy crust, making it a fascinating subject for scientific inquiry. On Earth, humans generally experience pressures up to about 1 atmosphere, equal to approximately 101.3 kilopascals (kPa) at sea level. To determine at what depth Europa’s ocean might exert a similar pressure, we need to consider the gravitational differences and the density of water.
Given Europa’s gravity is about 1.315 m/s², which is roughly one-seventh of Earth’s gravity (9.8 m/s²), the pressure at any given depth would accumulate more slowly on Europa than on Earth. On Earth, every 10 meters of water equivalent results in an increase of roughly 1 atmosphere of pressure.
Using the pressure formula \( P = \rho \cdot g \cdot h \), where \( P \) is pressure, \( \rho \) is the density of water (about 1000 kg/m³ for both Earth and Europa, assuming similar compositions), \( g \) is the gravitational acceleration, and \( h \) is the depth, we can calculate the necessary depth for Europa.
On Earth, 10 meters results in an additional 1 atmosphere due to the gravitational force and water density:
\[
P_{\text{Earth}} = 1000 \, \text{kg/m}^3 \cdot 9.8 \, \text{m/s}^2 \cdot 10 \, \text{m} = 1 \, \text{atm}
\]
For Europa:
\[
P_{\text{Europa}} = 1000 \, \text{kg/m}^3 \cdot 1.315 \, \text{m/s}^2 \cdot h = 101.3 \, \text{kPa}
\]
Solving for \( h \) gives:
\[
h = \frac{101.3 \, \text{kPa}}{1000 \, \text{kg/m}^3 \cdot 1.315 \, \text{m/s}^2} \approx 77 \, \text{meters}
\]
Therefore, you would need to go down to about 77 meters beneath Europa’s ocean for the water pressure to equal 1 atmosphere, the typical pressure experienced at sea level on Earth. This insight contributes to our understanding of the conditions within Europa’s ocean, which is a key factor in assessing the moon’s potential for supporting life.