What happens at perihelion in a planet's orbit?

At perihelion, a planet reaches the point in its orbit that is closest to the Sun. According to Kepler's laws of planetary motion, specifically the second law (the law of areas), a planet moves faster when it is nearer to the Sun. This means that at perihelion, not only is the planet at its minimum distance from the Sun, but it is also traveling at its maximum orbital speed. This phenomenon is a fundamental principle of planetary motion, reflecting the gravitational dynamics at play in the solar system.

The other options do not accurately describe the conditions of a planet’s orbit at perihelion, as perihelion distinctly involves both proximity to the Sun and increased orbital speed, rather than describing a farthest point, constant speed, or a circular orbit.