Which astronomical model places the Sun at the center of the solar system with planets orbiting around it?

• A. Geocentric model
• B. Heliocentric model
• C. Rotation
• D. Ocean Basin

Answer: (B)

This question tests understanding of how the solar system is organized. The Sun-centered model, known as the heliocentric model, places the Sun at the center and has the planets orbiting around it in paths shaped by gravity. This arrangement explains why planets follow smooth, oval (elliptical) orbits and why we can see features like the phases of Venus and occasional retrograde motion when observed from Earth. The geocentric model, by contrast, puts Earth at the center and uses complex motions to account for observations, which doesn’t align with how the planets actually move. The remaining options aren’t models of the solar system’s structure at all—rotation describes motion, and an ocean basin is unrelated geography. So the Sun-centered heliocentric model is the correct description.