🔍 Key Concepts

• Perihelion means the point where Earth is closest to the Sun in its orbit • Different "year" definitions are based on what reference point you use: fixed stars, equinox, or orbital position like perihelion • How Earth’s elliptical orbit and precession cause different year lengths

💭 Think About

• Ask yourself: which type of "year" is defined by going from one closest-approach-to-the-Sun point back to the next closest-approach? • Consider which of the year types is tied to the Sun’s apparent position against the stars, and which is tied to a special point in Earth’s elliptical orbit. • Eliminate any option that is just a general term for a year without specifically referring to the shape or special points of Earth’s orbit.

✅ Before You Answer

• Match the definition: perihelion to perihelion must relate to the Earth–Sun distance, not just the position of the Sun against the stars. • Check which term is explicitly defined in navigation/astronomy references as involving the ellipse of Earth’s orbit and its changing orientation. • Be sure you can clearly distinguish sidereal year (linked to stars) from the one linked to perihelion.