Final answer:
The average distance from the Earth to the planet Mercury varies due to its elliptical orbit around the Sun.
Step-by-step explanation:
The average distance from the Earth to the planet Mercury varies due to the planet's elliptical orbit around the Sun.
The semimajor axis of Mercury's orbit is 58 million kilometers, or 0.39 astronomical units (AU).
However, because of its high eccentricity of 0.206, Mercury's actual distance from the Sun varies from 46 million kilometers at perihelion to 70 million kilometers at aphelion.