What is the reason why Earth today has the slowest speed of the year?

Created by Vítor Martins on July 6, 2018 | 0 comments

Probably not noticed but today, July 6th, the Earth will be farther away from the Sun than any other day this year 2018.

So, that day, the planet will reach its aphelion which corresponds to the point farther from its star. But let's take a closer look at these dynamics.

Aphelium, from the Latin "aphelium", derived from the Latin "apos", which means far away, is the point of the orbit in which a planet or smaller body of the solar system is further away from the sun [19659005] 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 of the orbit where Earth is closest to the star [19659006] Nayra Rodríguez Eugenio, astrophysicist and professor at the Canary Islands Institute of Astrophysics, Tenerife, Spain

.Au 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 circumference, our planet describes an elliptical trajectory. As a result, the gravitational pull force between the Sun and the Earth varies along the orbit – and the orbital speed of the Earth changes as a function of its distance from the Sun.

Speed ​​

Aphelion occurs every year between July 2nd and 7th. Perihelion was January 3rd.

The Earth reached its greatest distance from the Sun on July 6 at 17:46 GMT, while the planet and its star were at 152,095,566 kilometers from one another [

As noted by the One of the so-called Kepler laws (on the planetary movements formulated by the German astronomer and mathematician Johannes Kepler in the 17th century), when the planets are close

Orbital translational velocity in aphelion will be 105,444 km / h, about 3,600 km less per hour than the speed of perihelion

The resorts of the year

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

The seasons arrive by tilting the axis. of the rotation of the Earth relative to the plane of the orbit around the Sun, which we call "ecliptic". "

Rodríguez Eugenio

This axis is tilted at about 23.5 degrees, so when we are in the northern hemisphere summer, the north axis, or north pole of the earth, tip more to the sun.In winter, our north pole is pointed in the opposite direction – not exactly opposite, about 23.5 degrees, "

More water in the southern hemisphere

The summer in the northern hemisphere is also part of aphelion, "but we receive more solar radiation in the US. northern hemisphere because the sun is higher on the

This could make us think that in the southern hemisphere the temperature rises more than in the south, and in the southern hemisphere, than in the north in summer because, besides tilting, the Earth is also closer to the Sun.

said Rodríguez Eugenio

But that's not what happens. "In the Southern Hemisphere there is a greater amount of water and that does not increase the temperature, "she says.

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

Thus, in In the & # 39; southern hemisphere and the north, the temperature is about the same, "says the & # 39; astrophysics.

Via