Perihelion: The Day Earth is Closest to the Sun

The Earth's orbit is not a perfect circle; because of that, there are times when the planet is closer to the star, there are also times when it is the opposite. However, most of the time, the distance remains the same. But, on the 2nd of January, 2021, at 13:51 (1:51 pm) Universal Time, the planet is at 91,399,453 miles/147,093,162 million kilometers away from the Sun, or 0.98 au (Astronomical Unit).

That is more or less 3% closer than the average distance between the Earth and the Sun. During that time period, it receives a significant increase of heat as more solar radiation is directed to the planet from its nearest star. Along with a hotter temperature, as long as there is no rain cloud in the area, the Sun is also comparatively brighter than usual. A welcome addition to places that experiences winter during the event.

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Perihelion

This is a cosmic phenomenon is an annual event called the Perihelion. From the Greek words peri meaning near and helios meaning sun, Perihelion is when the Earth's orbit is nearest to the Sun.

Perihelion also occurs at moments when the Earth is at its fastest movement while circumnavigating its orbit.

However, despite being closer to the scorching ball of gases, why were there no significantly intense global heatwaves?

Where are the heatwaves?

Although the Earth indeed receives more heat due to the intense solar radiation brought by being closer to the Sun, the Perihelion's effects are felt depending on the area a place is located. Also, the temperatures, specifically the weather and the seasons, are not determined by how close the planet is to the Sun. It is the Axial tilt (the slight tilt of the Earth) that determines the coldness or the hotness of a geographic location.

That tilt determines how much amount of sunlight the hemispheres get. It also determines how long the days or the nights each day of the year gets. During this year's Perihelion, the southern hemisphere is tilted closer to the Sun while the south is tilted away.

Despite receiving "extra" heat waves, an amount more than the usual dosage of solar radiation Earth gets, Earth is actually on its coolest during the cosmic event. A large part of the southern hemisphere happens to consist of oceans and other bodies of water. The ocean absorbs and soaks-up the extra heat, and that reaction negates the impact of the excess perihelion heat.

Even if the extra heat is already being dealt off by the planet's natural coping mechanism and internal defenses, the solar occurrence still has a visible impact nonetheless. During Perihelion, skies all over the world, including the northern hemisphere, the one tilted away from the Sun, are relatively clearer.

Aphelion

If Perihelion is the point in the orbit when the Earth is closest to the Sun, the moment when it is in the farthest is called aphelion (from Greek words aphe meaning away and helios meaning Sun).  This year's aphelion will be on the 5th of July, 2021.

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