'Perihelion' could only be coined after Copernicus — Greek 'peri' (near) + 'helios' (sun). Closest approach.
The point in the orbit of a planet, comet, or other celestial body at which it is closest to the Sun.
Coined in New Latin as perihelium by Johannes Kepler around 1596, from Greek peri (περί, near, around) + hēlios (ἥλιος, sun). The Greek hēlios derives from PIE *sóh₂wl̥ (sun), the same root that gives Latin sōl, Gothic sauil, Old English sigel, and Sanskrit sū́rya. The word was formed by direct analogy with perigee (nearest point to Earth, from Greek gē 'earth'), replacing the geocentric element with a heliocentric one to reflect the Copernican revolution's new understanding
Earth reaches perihelion — its closest point to the Sun — in early January, during the Northern Hemisphere's winter. This counterintuitive fact demonstrates that seasons are caused by the Earth's axial tilt, not by distance from the Sun. At perihelion, Earth is about 147.1 million kilometres from the