Rotation of the earth around the sun

The average distance from the Earth to the Sun is approximately 150 million kilometers. But since rotation of the earth around the sun occurs not in a circle, but in an ellipse, then at different times of the year the Earth is either a little further from the Sun, or a little closer to it.

In this real time-lapse photo, we see the path the Earth makes in 20-30 minutes relative to other planets and galaxies, rotating around its axis.

Change of seasons

It is known that in summer, in the hottest time of the year - in June, the Earth is about 5 million kilometers farther from the Sun than in winter, in the coldest season - in December. Hence, change of seasons happens not because the Earth is further or closer to the Sun, but for another reason.

The Earth, in its translational motion around the Sun, constantly maintains the same direction of its axis. And with the translational rotation of the Earth around the Sun in orbit, this imaginary earth's axis is always inclined to the plane of the earth's orbit. The reason for the change of seasons is precisely the fact that the Earth's axis is always inclined to the plane of the Earth's orbit in the same way.

Therefore, on June 22, when our hemisphere has the longest day of the year, the Sun also illuminates the North Pole, and the South Pole remains in darkness, since the sun's rays do not illuminate it. While summer in the Northern Hemisphere has long days and short nights, in the Southern Hemisphere, on the contrary, there are long nights and short days. There, therefore, it is winter, where the rays fall "obliquely" and have a low calorific value.

Time difference between day and night

It is known that the change of day and night occurs as a result of the rotation of the Earth around its axis, (more details:). A time difference between day and night depends on the rotation of the earth around the sun. In winter, December 22, when the longest night and the shortest day begin in the Northern Hemisphere, the North Pole is not illuminated by the Sun at all, it is “in darkness”, and the South Pole is illuminated. In winter, as you know, the inhabitants of the Northern Hemisphere have long nights and short days.

On March 21–22, the day is equal to the night, the vernal equinox; the same equinox autumn- happens on September 23rd. These days, the Earth occupies such a position in its orbit relative to the Sun that the sun's rays simultaneously illuminate both the North and South Poles, and they fall vertically on the equator (the Sun is at its zenith). Therefore, on March 21 and September 23, any point on the surface of the globe is illuminated by the Sun for 12 hours and is in darkness for 12 hours: day and night all over the world.

Climatic zones of the Earth

The rotation of the Earth around the Sun explains the existence of various climatic zones of the Earth. Due to the fact that the Earth has a spherical shape and its imaginary axis is always inclined to the plane of the earth's orbit at the same angle, different parts of the earth's surface are heated and illuminated by the sun's rays in different ways. They fall on separate areas of the earth's surface at different angles of inclination, and as a result, their calorific value in different zones of the earth's surface is not the same. When the Sun is low above the horizon (for example, in the evening) and its rays fall on the earth's surface at a small angle, they heat very little. On the contrary, when the Sun is high above the horizon (for example, at noon), its rays fall on the Earth at a large angle, and their calorific value increases.

Where the Sun is at its zenith on some days and its rays fall almost vertically, there is the so-called hot belt. In these places, animals have adapted to the hot climate (for example, monkeys, elephants and giraffes); tall palm trees, bananas grow there, pineapples ripen; there, under the shadow of the tropical Sun, spreading their crown widely, there are gigantic baobab trees, the thickness of which in girth reaches 20 meters.

Where the sun never rises high above the horizon, there are two cold zones with poor flora and fauna. Here the animal and plant world is monotonous; large areas are almost devoid of vegetation. Snow covers boundless expanses. Between the hot and cold zones are two temperate belts, which occupy the largest areas of the surface of the globe.

The rotation of the Earth around the Sun explains the existence five climatic zones: one hot, two moderate and two cold.

The hot belt is located near the equator, and its conditional boundaries are the northern tropic (the tropic of Cancer) and the southern tropic (the tropic of Capricorn). The conditional boundaries of the cold belts are the northern and southern polar circles. Polar nights last there for almost 6 months. Days are the same length. There is no sharp boundary between the thermal zones, but there is a gradual decrease in heat from the equator to the South and North Poles.

Around the North and South Poles, huge spaces are occupied by continuous ice fields. In the oceans washing these inhospitable shores, colossal icebergs float (more:).

North and South Pole explorers

Reach North or South Pole has long been a daring dream of man. Brave and tireless Arctic explorers have made these attempts more than once.

So was the Russian explorer Georgy Yakovlevich Sedov, who in 1912 organized an expedition to the North Pole on the ship St. Foca. The tsarist government was indifferent to this great undertaking and did not provide adequate support to the brave sailor and experienced traveler. Due to lack of funds, G. Sedov was forced to spend the first winter on Novaya Zemlya, and the second on. In 1914, Sedov, together with two companions, finally made the last attempt to reach the North Pole, but the state of health and strength changed this daring man, and in March of that year he died on the way to his goal.