Which orbital point is the furthest from the Sun for a planet's orbit?

• A. Perihelion
• B. Aphelion
• C. Apogee
• D. Perigee

Answer: (B)

When a planet orbits the Sun, its distance varies because the orbit is an ellipse with the Sun at one focus. The closest point to the Sun is called perihelion, and the farthest point is called aphelion. Terms like apogee and perigee describe orbits around the Earth, not the Sun, so they don’t apply to a planet’s Sun-centered orbit. Therefore, the furthest point from the Sun in a planet’s orbit is aphelion. For reference, Earth’s perihelion and aphelion are about 147 million km and 152 million km from the Sun, respectively.