Perihelion (noun)

The point in the orbit of a planet or comet where it is nearest to the sun.

Origin:

From the greek words peri "around" + hēlios "sun".

Examples:

1. Earth reaches its perihelion in early January.
2. Mercury"s perihelion is much closer to the sun than Earth"s.
3. The comet will be at its perihelion in the next month.
4. The asteroid's perihelion is closer to the sun than any other known asteroid.
5. The spacecraft observed the planet at its perihelion.