What is a supernova? What happens when a supernova explodes?

65 million years ago, a meteorite that is about 10 kilometers in diameter fell from the sky and hit near what is now the Yucatan Peninsula in Mexico. It triggered a huge tsunami and wildfires, and the dust it raised covered the sky and the sun. The earth's climate deteriorated greatly, eventually leading to the death of a large number of animals and plants. The dinosaurs that had lived on the earth for 160 million years could not escape this catastrophe, and they completely disappeared from the earth and turned into fossils.

The demise of the dinosaurs has made human beings feel the danger of "thorns on the back" at all times, because there are a huge number of meteorites and asteroids in our universe. If the earth is hit by meteorites and asteroids again, Then humans will be extinct. Humans still remember the collision of the century that occurred in 1994, when a comet named "Shoemek-Levi 9" crashed into Jupiter and released 40 trillion tons on the surface of Jupiter. The energy is equivalent to the total energy released by the explosion of 2 billion Hiroshima atomic bombs at the same time. This incident has once again aggravated mankind's sense of crisis, to the point of "discoloration". In order to prevent mankind from encountering the same fate as the dinosaurs, mankind has Most of the funds, instruments and energy are invested in monitoring asteroids, hoping to prepare and defend in advance before asteroids hit the earth. Since celestial body impacts occur from time to time, they involve a lot of human energy, causing human beings to Other dangers in the universe are often ignored, including supernova explosions that have not attracted human attention so far. So what is a supernova explosion?

A supernova explosion is an extremely violent explosion phenomenon that occurs when a star reaches its later stages of growth. This big explosion not only releases very bright light, but also releases huge cosmic rays, such as gamma rays. , although gamma rays may not have any impact on the earth, they are extremely harmful to life on the earth, because the penetrating power of gamma rays is very strong. Once the human body is exposed to a large amount of gamma rays, it will be Internal organs are damaged within two weeks, and they die within two weeks. Not only animals cannot withstand the exposure to gamma rays, but even plants cannot withstand it. If the earth is hit by a large number of gamma rays, there will be widespread death of animals and plants on the earth. phenomenon, and ultimately lead to biological extinction.