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This Friday, July 6th, we will be at our furthest point from the Sun in 2018.
On that day, the Earth will cross what is called aphelion, word of mouth. Greek origin meaning "far from the sun".
The aphelion is the point of Earth's orbit around the Sun in which the Earth is farthest from our star and perihelion (near the Sun) is just the opposite point, c & # 39; that is to say the point of the orbit of the Earth. The Earth is closer to the Sun, "says 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 the orbit of the Earth around the Sun is not a perfect but elliptical circumference
In the aphelion," the Earth is a little more l ejos , 5 million km farther from the Sun ", than in perihelion.
Velocity
The aphelion takes place every year between July 2 and 7. Perihelion has had place this year January 3.
The largest 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.
The Longest Distance
As Keple's second law emphasizes, when the planets are close to the Sun in their orbit, they move faster than when they are farther away
. aphelion means that the orbital translation velocity will be less than 103,536 km / h, so it is more than 7,000 km / h less than perihelion speed.
Seasons
The greater or lesser distance to the Sun during aphelion or perihelion does not correspond to temperature variations during the seasons.
"The seasons are produced by tilting the axis of rotation of the Earth relative to the plane that she describes around the Sun, which is what we call the ecliptic ", said Rodríguez Eugenio
" This axis is inclined at about 23.5 degrees and so when we are in the northern hemisphere summer, the north axis, it is to say the North Pole of the Earth, points more towards the direction of the Sun. "
" On the other hand in winter, our north pole points in the opposite direction, it is not because that they are about 23.5 degrees, but they are pointing away from 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 because the sun is higher than the horizon and we have on the other hand, the summer coincides with perihelion
"This could make us think that in the southern hemisphere the temperature rises more in the north in summer, because outside the inclination, the Earth is also closer to the Sun ", explains Rodríguez Eugenio.
But it is not like that
What happens is that "in the southern hemisphere there is more of water and that means the temperature does not increase much ".
because the earth warms much more easily than water and, because the southern hemisphere has a greater proportion of its surface covered by water, excess energy is absorbed by it. "
Therefore, in summer in the southern hemisphere and in the northern hemisphere, the temperature is about the same, explains astrophysics.
(from BBC) [19659026]
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