Astronomy Practice Exam

At what point in its orbit is the Earth furthest from the sun?

1. Apoapsis

2. Perihelion

3. Synodic

4. Aphelion

The correct answer is: Aphelion

The Earth is furthest from the Sun at a point in its orbit known as aphelion. During aphelion, which occurs once each year, the distance between the Earth and the Sun reaches its maximum. This position occurs because the Earth's orbit around the Sun is not a perfect circle but rather an ellipse. In this elliptical orbit, the distances between the Earth and the Sun change as the Earth moves along its path. The term "aphelion" specifically refers to the point in the orbit of a celestial body where it is the most distant from the Sun. For the Earth, this typically takes place in early July. The other terms mentioned have specific meanings related to orbits but do not indicate the point of maximum distance from the Sun: perihelion refers to the closest point to the Sun, synodic describes a type of astronomical cycle, and apoapsis is a more general term applicable to any orbit (not specifically Earth-Sun) where the body is furthest from the focus around which it orbits. Thus, recognizing that aphelion is the correct terminology for when Earth is at its furthest from the Sun clarifies why this is the right answer.