Listen to part of a lecture in an introductory astronomy class. The professor is discussing the possibility of life on Jupiter's moon Europa.
Professor: Now, one of the most exciting discoveries in recent planetary science is the strong evidence for a liquid water ocean beneath the icy crust of Europa. This ocean is thought to be in contact with a rocky seafloor, which provides the minerals and chemical energy necessary for life, much like the hydrothermal vents on Earth. Scientists believe that tidal heating, caused by Jupiter's gravitational pull, keeps the water from freezing solid. However, there are challenges. The ice layer is several kilometers thick, making it difficult to access the ocean below. Future missions are being planned, such as the Europa Clipper, which will fly by and analyze the moon's surface and thin atmosphere, but they won't be able to drill through the ice. So, while Europa remains one of the most promising places for extraterrestrial life, we still need more data. Any questions?
❓ 题目 What is the main reason scientists believe Europa's ocean could support life?
A. A. The ocean is very close to the surface and easily accessible.
B. B. The ocean is in contact with a rocky seafloor, providing minerals and chemical energy.
C. C. Tidal heating causes the ice crust to melt completely.
D. D. The ocean contains hydrothermal vents similar to those on Mars.
✅ 正确答案
B. The ocean is in contact with a rocky seafloor, providing minerals and chemical energy.