What is the danger to the earth? What dangers the planet is facing right now

1. Climate change.

Likelihood of a temperature increase of more than 2 degrees Celsius in the next 70 years: High risk factor: 6

2. Telomere loss.

Likelihood of a sharp decline in the population due to telomere loss in the next 70 years: Low risk factor: 8

3. Viruses. Likelihood of a deadly virus in the next 70 years: very high risk factor: 3

Fourth, terrorism.

Likelihood of a major terrorist attack in the next 70 years: Very high risk factor: 2

5. Nuclear war.

Likelihood of a global nuclear war in the next 70 years: low.

Risk factor: 8

6. Meteorite impact.

Likelihood of the Earth being hit by a large meteorite in the next 70 years: Medium risk factor: 5

Seventh, the robot is mainly anti-customer.

Likelihood of the emergence of high-IQ robots in the next 70 years: high.

Risk factor: 8

8. Cosmic rays.

Likelihood of a supernova explosion in the next 70 years: low.

Risk factor: 4

9. Supervolcanoes.

Likelihood of a supervolcanic eruption in the next 70 years: Very high risk factor: 7

10. Black holes. The likelihood that the Earth will be swallowed by a black hole in the next 70 years: extremely low.

In 1910, the earth once passed through the tail of Halley's comet, but the material density of the comet tail was extremely low, like a swallow flying through the smoke, nothing happened, but as ahwei3 predecessors said, if it was a head-on collision, it was the end of the game.

I remember that around the end of the 80s, there was a small asteroid that passed by the Earth at a very high speed, because it was so fast, it entered the Earth's atmosphere and flew out quickly. At that time, in North America, many people saw it during the day. However, it is not large and does not pose much of a threat to the earth.

At most, it is just a record for the size of a meteorite.

The impact before human history is unknown, but there are certainly any. Yesterday NASA also released a **, which is the crater of Mars' first moon Phobos, which gives people a shocking feeling, and the crater is about one-third the size of Phobos. If the landlord is interested, you can go here to see its Chinese version** and description:

It is conceivable that in the early days of the solar system, the Earth must have suffered a lot of impacts. And there are now quite a few people who believe that the Gulf of Mexico is where the asteroid that caused the extinction of the dinosaurs hit in the first place. On the map, the Gulf of Mexico does look like a crater.

Human history is too short for astronomical significance. And the history of astronomical records is even shorter. So the "near" events that occurred in the past in the history of the earth are unknown.

It is probably recorded that in 1910 the Earth passed through the tail of Halley's Comet. If you collide with it head-on, you're done.

The Great Comet Collision has turned a page in history, but the warning and enlightenment left for the earth is thought-provoking.

Will the Earth experience such a catastrophic collision, and how likely is it?

If one day encounters, will humanity be able to overcome it?

Will the Earth spacecraft be killed in such a cosmic traffic accident?

How many restless people like comets and meteoroids are there? Is it a threat to the planet? Asteroids are also an indispensable player in this competition.

On New Year's Day 1801, Italian astronomer Piazzi discovered a new planet between the orbits of Mars and Jupiter, which opened the prelude to the discovery and study of asteroids. From the first Ceres, Homo sapiens, marriage, Vesta, ......Throughout the 19th century, more than 400 were discovered, and in the 20th century, asteroid discoveries became more frequent. So far, astronomers have discovered as many as 5,000 of them.

Among them, nearly 3,000 have been measured and numbered. It is estimated that modern astronomical telescopes have discovered fewer than a few thousandths of the total number of asteroids.

Although there are many of them, these asteroids are small in size and mass. The largest planet, Ceres, is only 770 kilometers in diameter, less than 1 4 in diameter of the Moon, and less than 1 450 in size than the Earth. The Hemez asteroid, discovered in 1937, is less than 1 kilometer in diameter and only half the height of Mount Tai.

So up to now, asteroids have all gathered into clusters, at best the size of a medium moon, which is really far from the size of a large planet.

Such a vast asteroid legion, most of them are concentrated in the asteroid belt between the orbits of Mars and Jupiter, very few go beyond this range, but there are also a few dishonest "pawns", running along the elliptical orbit, far away can run to the space outside Jupiter, or even beyond the orbit of Saturn, but in the near stride into the Earth's orbit, and even deep into the orbit of Venus, as a "near-Earth asteroid", become a stable element of the Sun family, and is likely to be the main "killer" of the earth in the future.

The orbital eccentricity of an asteroid near Earth asteroid is generally relatively large, and in terms of the distance between it and the Earth, it is generally a few hundred kilometers to 50 million kilometers at the closest, and it is rare to get close to one million kilometers. In October 1937, the asteroid Herm passed 800,000 kilometers away from the earth, which is only twice the distance between the moon and the earth, and in March 1989, there was also an asteroid that flew 750,000 kilometers away from the earth and moved away from us. With so many asteroids moving around the space near the Earth, it really makes people sweat.

Earth's evolution can be broadly divided into three stages. The first stage is the period of formation of the Earth's sphere, which is roughly 4600 to 4200 mA [million years]. When the earth was first born, it was very different from what it is today.

Scientists theorize that the Earth began as a red-hot ball of liquid material, mainly magma. Over time, the temperature of the earth's surface continues to drop, and a solid core gradually forms. The dense material moves towards the center of the earth, and the less dense material (rocks, etc.) floats on the surface of the earth, which forms a earth whose surface is mainly composed of rocks.

The second stage is the Archean, Proterozoic period. Its time limit is between 4200 and 543 MA. The earth is constantly releasing energy outward.

Gases such as water vapor and carbon dioxide released by the continuous eruption of high-temperature magma constitute a very thin early atmosphere --- primitive atmosphere. As the water vapor in the primeval atmosphere continues to increase, more and more water vapor condenses into small water droplets, which then converge into rainwater and fall to the surface. And just like that, the primordial ocean was formed.

The third stage is the Phanerozoic period, which lasts from 543 mA to the present. The duration of the Phanerozoic is relatively short, but during this period, the organisms and their flourishing, the geological evolution is very rapid, the geological processes are rich and colorful, and the geological bodies are all over the world, widely preserved, which can be observed and studied very well, and are the main research objects of geological science, and the basic theories and basic knowledge of geology have been established.

In order to prove the origin of life and the earth, various hypotheses have been proposed to explain the birth of life through experiments and speculation. In 1953, Stanley, a young American scholar, used a closed device filled with methane (CH4), ammonia (NH3), hydrogen (H2) and water (H2O) in the laboratory to simulate the environmental conditions of the primitive earth by discharging and heating, and synthesized some amino acids, organic acids and urea and other substances, which caused a sensation in the scientific community. The results of this experiment show even more convincingly that the early earth was fully capable of giving birth to living organisms, and that primitive living matter could be produced under natural conditions without life.

Some organic substances in the primitive ocean, after long-term and complex chemical changes, gradually formed larger and more complex molecules, until the basic substances that make up living organisms--- proteins, and macromolecular substances such as nucleic acids as genetic material. Under certain conditions, substances such as proteins and nucleic acids are concentrated, condensed, etc., forming a system composed of a variety of molecules, with a membrane on the outside, separated from seawater, and undergoing long and complex changes in seawater, and finally forming primitive life.

In short, the evolution of the earth led to the birth of life on the earth. Collapse.

It is the growth data of the plant.

The alien planet's atmosphere is about to disappear.

So I want to snatch the earth.

But the siblings' parents disagreed, believing that they could grow a plant on Earth, and if the plant survived, it would create a new atmosphere so that they would not have to invade the Earth.

They set up a laboratory on Earth to cultivate alien plants, and they succeeded, and the siblings came to get the growth data of the plants and bring them back.

But the alien military still wanted to directly occupy the earth, so they sent a killer to finally go back with the information.