How blessed is the Earth in the solar system?

Earth is the four terrestrial planets on the periphery of the Sun.

One of these planets from near to far is Mercury.

Venus, Earth and Mars. We can see the Earth's presence in the solar system by comparing the properties of Venus and Mars on adjacent Earths.

Privileged location. Human beings have searched for extraterrestrial life for decades and found almost nothing, while life on Earth is full of life, which shows the importance of the earth's environment to the evolution of life, and its unique position in the solar system.

First of all, the earth is in the habitable zone of the sun, the so-called habitable zone is far from the sun, not too far away will not be very cold, water can remain liquid, liquid water is indispensable for the survival of life on the earth, and substances can only be bioavailable in water.

But the Earth is not too close to the Earth's atmosphere.

Won't be stormed by the sun.

Blowing away, the water will not evaporate, solar storms contain a large number of high-energy particle beams, and the aurora on Earth is a wonderful phenomenon formed by the interaction of charged particles and the earth's atmosphere, while the heat from the sun can be retained by the earth's atmosphere. So that the temperature difference between the night and day of the earth is not too large.

The light of the sun provides energy for the growth of plants, plants become food for animals, and after death, animals become food for microorganisms and scavengers, and finally the remains are broken down into small molecules and returned to the environment, and biological systems and the environment form a cycle of energy. At the same time, the sun's rays can partially penetrate the earth's atmosphere, without harming the earth's life, promoting the genetic mutation of species, and the continuous evolution of organisms. Without such a unique environment, life would not have arisen, and without the sun life could not survive and even evolve.

And the main sequence star of the Sun.

The stage can last for tens of billions of years, and it also ensures that the earth's environment can remain relatively stable for a long time, not too hot, not too cold.

Galaxy. There are 100 billion galaxies in the universe, each galaxy has an average of 100 billion stars, and the total number of planets in the habitable zone is staggeringly large, so many scientists also have a positive view of the existence of aliens.

There are many stars in the center of the galaxy, and the mass is large enough that only the massive stars can have a supernova explosion that throws heavy elements into space. So that there are enough heavy elements here to form rocky planets and the heavy elements necessary for life.

The earth is not far from the sun, the temperature is just enough to reach the temperature suitable for the survival of organisms, and the solar radiation can also be well stored by the earth.

The earth is located in the "three rings" of the solar system, and the light and hot water conditions are relatively moderate.

Very blessed. Because the earth is located in a habitable zone, and it is just right for the birth of life, it is very blessed.

Position of the Earth in the Solar System:The Sun is located at the center of the system, and the Earth is the third farthest planet from the Sun, with Venus in front and Mars in the back.

Born 100 million years ago, Earth is the third planet in the solar system from the inside to the outside, and it is also the terrestrial planet with the largest diameter, mass, and density in the solar system. It is surrounded by an atmosphere and the surface is land and sea.

The solar system is a system of celestial bodies centered on the sun and bound by the sun's gravitational pull, including the sun, planets and their moons, dwarf planets, asteroids, comets and interplanetary matter. The solar system is located about 10,000 light-years from the center of the Milky Way (the Sun is just one of the stars in the Milky Way, which is about 100 billion to 400 billion).

The earth's mineral and biological resources sustain the global population, and it is the only celestial body in the universe known to mankind to have life. Life was born within a billion years of the birth of the Earth. Since then, the Earth's biosphere has changed the atmosphere and other environments, allowing for the birth of organisms that need oxygen and the formation of the ozone layer.

The ozone layer, along with the Earth's magnetic field, blocks harmful rays from the universe and protects life on land.

The internal structure of the earth refers to the layered structure of the earth's interior. According to the change in the propagation velocity of ** waves at different depths underground, the interior of the earth is generally divided into three concentric spheres: the core, the mantle and the crust.

The central layer is the core; In the middle is the mantle; The outer layer is the earth's crust. The crust and mantle are bounded by the Moho plane, and the mantle and core are bounded by the Gutenberg plane. **Usually occurs in the earth's crust.

Earth is the third planet in the solar system from the inside to the outside, and it is also the terrestrial planet with the highest diameter, mass, and density in the solar system. It is also often referred to as the world. The English word earth comes from Old English and Germanic languages.

The Earth is 4,446 billion years old and has a natural satellite, the Moon, which revolves around the Earth in a celestial cycle, while the Earth rotates in a period of 23 hours 56 min4s (close to one solar day 24 hours) and orbits the Sun in a one-year cycle.

The Solar System (The diagram includes the nine planets centered on the Sun and orbiting the Sun in their respective orbits.) In the solar system, the sun accounts for the total mass of the solar system, and it has a strong enough gravitational pull to attract other celestial bodies, shapes.

Diagram of the solar system and planets.

into a celestial system centered on it. The nine planets, in descending order of distance from the Sun, are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto (table.

Table Average distances of the nine planets from the Sun.

There is also an asteroid belt of tens of millions of asteroids in the solar system, which, like the nine planets, orbit the sun in a certain orbit. The nine planets, with the exception of Mercury and Venus, which are closest to the Sun, are accompanied by their own moons, such as the Moon, which is a satellite of the Earth. In addition to planets and moons, the solar system includes comets and meteoroids.

The closest approach of the Earth to the Sun (July 2) was 14710 104 km. In addition to revolving around the Sun, the Earth also rotates in a certain period, with an average rotation of 24 hours. If the role of the Earth and other stars is not considered, the path of the Earth around the Sun is a closed curve, called the Earth's orbit.

The Earth's orbit is actually the orbit of the Earth's center. The Earth's orbit is an ellipse, and its semi-major axis (a) is 149600000 km; semi-minor axis (b) 149,580,000 km; Half focal length (c) is 2500000 km; The circumference (l) is 940000000 km. The shape of the Earth's orbit is elliptical, its eccentricity (i.e. e=c a) is or 1 60, and its flattening rate (i.e. f=(a-b) a) is 1 7000.

The eccentricity and flattening of the Earth's orbit are small and close to circular. The time it takes for the earth to make one revolution around the sun is d.

The first is due to the fact that the Earth receives a steady stream of sunlight; Due to the isotropy, coplanarity, and near-circularity of the eight planets of the solar system, the eight planets do not interfere with each other and are in a relatively stable cosmic environment.

Then there is the condition of the earth that is more suitable for the late sphere compared to other planets:

1.The distance between the sun and the earth is moderate, and the temperature of the earth's surface is suitable, about 15, which ensures that there is liquid water on the earth and creates better environmental conditions for the survival of organisms. Because Mercury and Venus are too close to the Sun, their surface temperatures are too high, and water exists in a gaseous state; Mars and Jupiter are too far from the Sun and have low surface temperatures, both below 0.

2.The rotation of the earth is moderate, so the alternation of day and night is moderate, and the temperature will not be too high during the day and too low at night.

In this regard, Mercury's rotation period is too long, and the temperature difference between day and night is too large, which is not suitable for living organisms. In the same way, Venus's rotation period is 243 days. Jupiter's rotation period is too short, only 9:50.

3.The mass of the earth is moderate in size, attracting the right amount of atmospheric concentration. Mercury, Venus, and Mars are too small to attract enough atmosphere, and also because of the thin atmosphere, Mercury, Venus and Mars are in a cosmic environment called unstable.

But Jupiter's mass is too large and attracts too much atmosphere, the outer atmosphere is too thick, and the greenhouse phenomenon inside is too violent for living things.

Earth is one of the planets in the solar system that orbits the sun. The average distance of the Earth from the Sun is about 100 million kilometers (i.e. 1 astronomical unit), and the orbital period is days. The time of one rotation of the Earth is 23 hours, 56 minutes and 4 seconds, which is the benchmark of a sundial.

The Earth is located between the inner and outer planets, and the inner planets include Mercury, Venus, Earth, and Huoliang, all of which are relatively close to the Sun, with smaller orbits and short orbital periods; The outer planets, including Jupiter, Saturn, Uranus, and Neptune, are farther from the Sun, have larger orbits, and have long orbital periods. There are changing relative position relationships between the Earth and other planets, and these positions are constantly changing over time.

The solar system is composed of the sun, 8 planets, more than 100 moons, many dwarf planets and countless small meteors, comets, and meteoroids.

The planets are in alphabetical order: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Mercury, Venus, Earth, and Mars, which are close to the Sun, are called terrestrial planets.

Their common characteristics are high density (>, small size, slow rotation, few satellites, mainly silicate (silicate) internal composition, and a solid shell. Jupiter, Saturn, Uranus, and Neptune, which are far from the Sun, are called Jovian planets.

Due to the moderate distance between the Earth and the Sun, the average temperature of the Earth's surface is 15, which is conducive to the occurrence and development of life processes.

Due to the Earth's mass and moderate mass, its gravitational pull can cause a large amount of gas to gather around the Earth, forming an atmosphere that surrounds the Earth. If the volume and mass are too small, the gravitational force will not be enough to retain a sufficient amount of gas, which will cause a large amount of gas to escape; Conversely, if the volume and mass are too large, the atmosphere on the planet's periphery will be too thick, making it difficult for solar heat to penetrate, resulting in low planetary surface temperatures.

Due to the decay of radioactive elements in the earth's interior and the heating of the earth or the contraction of the original earth's gravity, the temperature of the earth's interior rises and the crystalline water vaporizes. The water vapor escaping from vaporization condenses and rains due to cooling during the rising process, and falls to the low-lying places of the ground, forming the primordial ocean, and the ocean is known as the cradle of life - the earliest single-celled life on earth appeared in the primordial ocean.

1. The earth, one of the eight planets in the solar system, is the third in order of being from the sun; 2. It has a natural satellite, that is, the middle rock of the moon, and the two form a celestial system, that is, the earth-moon system; 3. The Earth, as a planet, originated from the primordial solar nebula 4.6 billion years ago, and the Earth would interact with other celestial bodies in outer space, including the Sun and the Moon; 4. The earth is home to millions of creatures, including human beings, and the earth is the only celestial body in the universe where life is known.