Listen to part of a lecture in an astronomy class. The professor is discussing the possibility of life on Jupiter's moon Europa.
Professor: For decades, scientists have speculated about life beyond Earth, and one of the most intriguing candidates in our solar system is Europa, one of Jupiter's large moons. Unlike Mars, which has a dry, barren surface, Europa is covered by a thick layer of ice. However, beneath that ice, there is strong evidence for a vast liquid ocean. How do we know this? Well, spacecraft flybys have detected a magnetic field that suggests a conductive layer, likely salty water, beneath the surface. Also, images show cracks and ridges on the ice, which indicate tidal flexing—the moon is stretched and squeezed by Jupiter's gravity, generating heat. This heat could keep the ocean liquid. So, why does this matter? On Earth, we find life in extreme environments, such as deep-sea hydrothermal vents, where sunlight never reaches. These ecosystems thrive on chemical energy. If Europa has similar conditions—liquid water, heat, and chemical nutrients—it might support microbial life. Some researchers even propose that plumes of water vapor, detected by telescopes, could be sampled by future missions to test for organic molecules. Clearly, Europa has become a priority target for astrobiology.
❓ 문제 What is the main reason scientists are interested in Europa as a potential habitat for life?
A. Its surface shows signs of recent volcanic activity.
B. It has a subsurface ocean that may contain liquid water and chemical energy.
C. Its atmosphere is similar to Earth's and could support human life.
D. It has large lakes of liquid methane on its surface.
✅ 정답
It has a subsurface ocean that may contain liquid water and chemical energy.
TOEFL Listening Tips
Skim the questions first to predict the content
Watch for signal words in lectures and conversations (however, actually, in fact)
For main idea questions, focus on the beginning; for detail questions, focus on examples and data
For attitude questions, pay attention to the speaker's tone and word choice
Take notes on keywords; don't try to write down every word
