Which term denotes the farthest point in a satellite's orbit from the Sun?

• A. Aphelion
• B. Wavelength
• C. Wind Duration
• D. Astronomical Tide

Answer: (A)

In orbital terms, aphelion is the farthest point in a satellite's orbit from the Sun. An ellipse has two special points: aphelion (the farthest) and perihelion (the closest). The Sun sits at one focus of the orbit, so as the body travels, it is furthest away at aphelion and closest at perihelion, with speed being slower at aphelion and faster at perihelion due to conservation of angular momentum. The other terms refer to unrelated ideas—wavelength (distance between wave crests), wind duration (time over which wind blows), and astronomical tide (tidal effects from Sun and Moon)—so they do not describe where the satellite is in its orbit.