Periheliliike

Periheliliike refers to the movement of an object in its orbit around a celestial body, specifically when it reaches its closest point to the central body. This point in the orbit is known as the periapsis. The term is derived from Greek, with "peri" meaning near and "helios" meaning the sun, so it specifically refers to the closest approach to the Sun in an elliptical orbit. While periheliliike is most commonly associated with planets orbiting the Sun, it can also describe the closest approach of any object to any central body, such as satellites orbiting Earth (perigee) or stars orbiting a black hole.

The speed of an orbiting object is not constant. According to Kepler's second law of planetary motion, an object in orbit sweeps out equal areas in equal times. This means that an object moves faster when it is closer to the central body and slower when it is farther away. Therefore, periheliliike is characterized by the object's maximum orbital velocity. The phenomenon of periheliliike is a fundamental aspect of orbital mechanics and is observed throughout the universe.