Which location is a promising place to search for life beyond Earth?

• A. On the surfaces of icy Jovian moons
• B. Beneath the surfaces of icy Jovian moons
• C. In the Oort cloud
• D. In the asteroid belt

Answer: (B)

Liquid water beneath an ice crust on icy Jovian moons provides a potential habitat because it offers the liquid medium life needs, along with chemical nutrients and possible energy sources. These moons are heated by tidal forces from their giant planet, which can keep subsurface oceans liquid far from the Sun, and they can host hydrothermal-like environments at the ocean floor that supply energy for biology. The surface environment is hammered by radiation and extreme cold, making it inhospitable, so the most promising places to look are where heat, water, and chemistry meet—the hidden oceans beneath the ice. In contrast, the Oort cloud is extremely distant and cold with little energy input, and the asteroid belt is mostly dry rock with scarce liquid water, making life less plausible there.