Astronomy has shown us that the Earth is just one planet orbiting an ordinary star in a vast universe.

• A. A place of central significance
• B. A unique, exceptional home
• C. Just one planet orbiting an ordinary star
• D. The only planet with oceans

Answer: (C)

Earth’s place in the cosmos is ordinary rather than central. Astronomy shows that our planet is just one world orbiting a fairly typical star, in a vast and expansive universe. This is in line with the Copernican idea that we do not occupy a special or privileged position in the cosmos—there are many stars and many planetary systems, not just ours.

The best option expresses this view by saying Earth is one planet orbiting an ordinary star in a huge universe. It avoids implying that Earth is uniquely significant, the sole home with oceans, or the only planet with life, all of which would contradict the broad, evidence-based picture of a widespread cosmos. While Earth does have oceans, we cannot claim it is the only world with oceans, and astronomy increasingly reveals a diversity of worlds around countless stars.