Why Earth's speed on Friday will be 7,000 km / h slower than January | Science and Health

That day, the planet will reach its aphelion, a word of Greek origin that means "far away". of the Sun. "

" Aphelion is the point of orbit around the Sun where the Earth is farthest from the star and perihelion (which means "near the Sun") is just the opposite, the point from the orbit where the Earth is closer to the star, "said Nayra Rodríguez Eugenio, astrophysicist and professor at the Canary Islands Institute of Astrophysics in Tenerife, Spain.

"In perihelion, the Sun is about 147 million kilometers from the Earth, in the aphelion is about 152 million kilometers from the Sun."

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

Aphelion occurs annually between July 2 and 7. Perihelion was January 3.

The Earth will reach its greatest distance from the Sun on July 6 at 17:46 GMT, while the planet and its star will be at 152,095,566 k ilometers one of the other.

Longest distance results in slower orbiting speed.

As noted in one of the so-called Kepler laws (on planetary movements, formulated by the German astronomer and mathematician Johannes Kepler in the 17th century), when the planets are close to the sun, they move more quickly when they are far away.

Orbital translation speed will be 103,536 kilometers per hour, more than 7,000 kilometers less per hour than perihelion velocity.

The reductions or increase in the speed of the Earth in the road around the Sun have nothing to do with the variations in temperature and climate of the seasons.

"The seasons occur by tilting the axis of rotation of the Earth relative to the plane of the orbit that is around the Sun, which we call" eclíptica "", said Rodríguez Eugenio

"This axis is inclined at about 23.5 degrees, so when we are in summer in the northern hemisphere, the north axis, or north pole of the Earth, is more oriented towards the sun. In winter, our north pole is pointed in the opposite direction – not exactly the opposite, about 23.5 degrees, but it is pointing in the opposite direction to the sun. "

The summer of the northern hemisphere coincides with the aphelion," but we are getting more solar radiation here in the northern hemisphere because the sun is higher at the # And we have more hours of sunshine, "he explains to astrophysics.

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 in the north in summer because, besides the slope, the earth is also closer to the sun", declared Rodríguez Eugenio

But that is not what happens

What happens, is that "in the southern hemisphere, there is more" water and that does not increase the temperature so much, "she says.

" This seems to be due to the fact that the earth heats up more easily than water, and that the southern hemisphere has a greater proportion of its territory when covered with water, excess energy is absorbed by it. "