Understanding Perihelion and Its Impact on Climate and Life

Perihelion is the point in the orbit of a planet, asteroid or comet where it is closest to the sun. At this point, the object is moving at its fastest speed and is closest to the sun's gravitational pull. The opposite point in the orbit is called aphelion, where the object is farthest from the sun and moving at its slowest speed.
Perihelion is an important factor in determining the climate and surface conditions of a planet or other celestial body. For example, Mercury, which has a highly eccentric orbit, experiences extreme variations in temperature between its perihelion and aphelion, with temperatures reaching as high as 800 degrees Fahrenheit (427 degrees Celsius) at perihelion and dropping to -290 degrees Fahrenheit (-179 degrees Celsius) at aphelion.
Perihelion is also important in determining the potential for life on a planet or other celestial body. For example, Earth's relatively stable climate and moderate temperatures are due in part to its relatively circular orbit and proximity to the sun, which allows for a stable water cycle and the presence of liquid water, both of which are essential for life as we know it.
Perihelion is not just limited to planets, asteroids and comets, even the moon has perihelion and aphelion. The Moon's perihelion is when it is closest to Earth and aphelion is when it is farthest from Earth.
It's important to note that the distance between the object and the sun at perihelion or aphelion does not determine the object's surface temperature, other factors such as the composition of the object, its atmosphere (if it has one) and the angle of the sun's rays also play a role in determining the surface temperature.