The Earth's orbit is elliptical: there are times when it is closer to the Sun and others when it is further away.
In addition, the axis of rotation of the planet is slightly inclined with respect to the plane of the orbit. At the end of the year it seems that the Sun rises and falls.
The apparent path of the Sun is called ecliptic, and it passes over the Earth's equator in early spring and autumn. These points are the equinoxes. In them day and night are equal. The ecliptic points farthest from the equator are called solstices, and signal the beginning of winter and summer.
Near the solstices, the sun's rays fall more vertically over one of the two hemispheres and heat it more. Is the summer. Meanwhile, the other hemisphere of the Earth receives the most inclined rays, they have to pass through more chunk of atmosphere and cool before reaching the ground. It is winter.
Like the entire Solar System, the Earth moves through space at about 20.1 km / s or 72,360 km / h towards the constellation of Hercules. However, the Milky Way as a whole, moves towards the constellation of Leo at 600 km / s.
Translation: The Earth and the Moon revolve together in an elliptical orbit around the Sun. The eccentricity of the orbit is small, so much so that the orbit is practically a circle. The approximate circumference of the Earth's orbit is 938,900,000 km and our planet travels along it at a speed of about 106,000 km / h.
Rotation: The Earth rotates on its axis once every 23 hours, 56 minutes and 4.1 seconds. Therefore, a point on the equator rotates at just over 1,600 km / h and a point on Earth at 45 ° N altitude, rotates at about 1,073 km / h.
A scheme to relate concepts:
Other movements: In addition to these primary movements, there are other components in the total Earth movement such as the precession of the equinoxes and the nutation, a periodic variation in the inclination of the Earth's axis caused by the gravitational attraction of the Sun and the Moon.
These concepts are expanded in the section on Earth and the Moon in two pages: one dedicated to the movements of translation and rotation and another dedicated to explain in greater detail the precession and nutation from the earth.
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