In the cover you can see the image of the Earth sent from space by the crew of the Apollo 17 spacecraft. Credit: NASA.
The planet Earth is one of the planets in the solar System
The average distance between the Earth and the Sun is one of the most important distances in the Solar System. It defines the astronomical unit (AU).
The AU is the standard, unanimously approved at the International Astronomical Union meeting in Beijing: is now 149,597,870,700 meters. Not one meter more, not one less.
In less than 500 years, the Earth has gone from being considered the center of the Universe to being classified as the fifth planet, in size, of a Sun that is nothing more than a small star within the Milky Way.
They are only smaller than the Earth: Venus, Mars, Mercury and Pluto.
But, there is no doubt that Earth is the most beautiful planet in the solar system
The Earth has a satellite that revolves around it: the Moon.
The Sun is huge, compared to the planets. Its equatorial diameter is 1,392,000 km. More than 100 times greater than that of Earth.
Pluto was the smallest planet, with an equatorial diameter of 2,302 km. It is now classified as a dwarf planet.
Jupiter is the largest solar planet, with an equatorial diameter of 142,984 km. Around it, 63 known moons revolve.
In this image, the Sun does not even appear as a point of color.
The sun compared to other stars
Antares, the brightest star in the constellation Scorpio, is 700 times larger than the Sun.
Aldebaran, the brightest star in Taurus, is 44 times larger than the Sun.
Betelgeuse, in the constellation Orion, is the ninth brightest star in the sky.
To travel the diameter of the Milky Way, traveling at 300,000 km per second, it would take 100,000 years.
The planet Earth is a beautiful place to live
Technological development has achieved extraordinary goals and the current inhabitants of this small planetary ship can contemplate with admiration how beautiful.
Land, naval and air transport has developed so much that people of all countries can better know their homeland, of which they are proud.
And many privileged people spend time and money to discover the wonders that exist in other countries and continents.
The Earth is beautiful and fertile in Africa, America, Asia, Europe, Oceania and Antarctica.
The human, with his intelligence, will finally manage, perhaps in thousands of years, to evolve towards a mentality that makes him respect nature and share the wealth of the Earth with his peers.
When a great majority of people understand the material insignificance of planet Earth and the shortness of human life, they will be able to see clearly how sad and ridiculous the fratricidal struggles between those of us who are for a brief moment “observers of the Universe” are.