Why on July 6 the Earth will travel 3,600 km / h more slowly

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NASA

This Friday, July 6, we will be at our furthest point from the Sun in 2018.

That day, the Earth will cross what is called aphelion a Greek word which means "far from the Sun" "

" The aphelion is the point of the Earth's orbit around the Sun where the Earth is farthest from our star and the perihelion ( near the Sun) is just the opposite, that is, the point of the orbit of the Earth in which the Earth is closer to the Sun, "explains BBC Mundo Nayra Rodríguez Eugenio Astrophysicist and disseminator of the Institute of Astrophysics of the Canaries

"In perihelion the Sun is about 147 million km from the Earth, and when it is in the & &,, aphelion, it is about 152 million km from the Sun. "

The distance varies because of the orbit of the Earth around the Sun. is not a perfect circumference but elliptical

The greater distance results in a lower speed

As Kepler's second law emphasizes, when planets are close to the Sun in its orbit move faster than when they are further away

The Longest Distance in the World Aphelion means that the translational orbital velocity will be less than 103,536 km / h, about 3,600 km / h less than the speed in the Perihelie . *

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NASA

In the aphelion, "the Earth is a little further, 5 million km further from the Sun", than in perihelion.

Speed ​​

The aphelion takes place every year between July 2 and 7. Perihelion took place this year on January 3. [19659023] Image copyright
NASA

The greatest distance between the Earth and the Sun will be recorded on July 6 at 17:46 GMT, while the planet and its star are at 152,095,566 km

Seasons

More or less the distance to the Sun during Aphelion or perihelion are not at all related to temperature variations during the seasons .

"The stations are produced by the tilt of the axis of rotation of ] T ierra relative to the aircraft that it describes around the Sun, what we call the ecliptic, "said Rodríguez Eugenio.

" This axis is tilted about 23.5 degrees and so when we are in the summer of l 39; northern hemisphere, the north axis, ie the north pole of the Earth, points more toward the direction of the Sun. "

" On the other hand, in winter, our north pole points in the opposite direction it is not exactly opposite since it is about 23.5 degrees, but it points in the opposite direction to the Sun. "

More Water In the Southern hemisphere

The summer of the northern hemisphere coincides with the aphelion, "but we receive more solar radiation here in the northern hemisphere as the sun is higher above the Horizon and we also have more hours of sunshine "as explained by astrophysics.

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NASA

In the southern hemisphere, on the other hand, summer coincides with perihelion .

"This could make us think that in the southern hemisphere the temperature rises more than north in summer, because apart from inclination, the Earth is also closer to the Sun", explained Rodríguez Eugenio.

But it's not like that.

What happens is that " in the southern hemisphere there to amount of water and this makes that the temperature does not increase so much.

"This seems to be because the earth heats up much more easily than water and, because the southern hemisphere has a greater proportion of its surface covered by water, the excess energy is absorbed by it. "[19659007Parenttimesinthehemisphereandinthehemisphereofthetemperatureisatthesametimeastheexplosiveastrophysics

The greater distance translates into a lower speed

As Kepler's second law emphasizes, when the planets are close to the Sun in their orbit, they move faster than when they are farther away.

Greater distance in the aphelion means that speed orbital translation will be less. of 103,536 km / h, about 3,600 km / hr less than the speed of [[Period] .

* This note was corrected on July 4, 2018. Although several means of pre nsa scientists have mentioned a difference of 7,000 km in the speed of the Earth between l '. aphelion and perihelion, the astrophile ísica Nayra Rodríguez Eugenio explained that the correct calculation indicates a change of speed of 3,600 km per hour.

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