The perihelion and aphelion are the nearest and farthest points respectively (apsides) of a body's direct orbit around the Sun.
The perihelion (n/) of any orbit of a celestial body about the Sun is the point where the body comes closest to the Sun. It is the opposite of aphelion (n/), which is the point in the orbit where the celestial body is farthest from the Sun.
The words perihelion and aphelion were coined by Johannes Kepler to describe the orbital motion of the planets.
The words are formed from the prefixes peri- (Greek: περί, near) and apo- (Greek: ἀπό, away from) affixed to the Greek word for the sun, ἥλιος.
Perihelion and aphelion are sometimes incorrectly used for the orbits of objects about bodies other than the Sun. The correct terms are: