Astronomers have discovered that a supernova explosion can lead to the complete destruction of life on a planet like Earth, even if it is 160 light-years away.
This is reported «The Astrophysical Journal».
The main reason is X-ray radiation, which continues to attack the planet for several decades after the explosion. This discovery was made as a result of observations of 31 supernovae and their consequences. Thus, supernovae that scientists previously knew were potentially dangerous are now being compared to the death star from Star Wars.
However, if the death star of Darth Vader destroyed the planet completely, then supernovae simply deprive it of all life. The results of the study were obtained using NASA’s Chandra X-ray Observatory, the Swift and NuSTAR and XMM-Newton telescopes of the European Space Agency.
According to new discoveries, the main threat associated with a supernova explosion is the shock wave that is generated during this event. This wave collides with the supernova’s dense surrounding gas and blasts large amounts of X-rays into space. Scientists say X-rays could reach planets like Earth that have life months or years after the explosion. The radiation intensity can be so high that it completely destroys life on the planet, especially considering that this “attack” can last for decades.
Although scientists are only guessing how long the deadly wave of radiation could be, they know for sure that the supernovae they observed hit exoplanets about 160 light-years away.
Scientists have long known about the dangers of supernovae. In the first days and months after the explosion, they emit intense radiation. However, there is another threat – energetic particles that can arrive hundreds and thousands of years after the explosion. It is known that X-rays can seriously change the chemical composition of the atmosphere of a planet like Earth. In addition, this radiation is capable of destroying the ozone layer, which protects life on the planet from harmful ultraviolet radiation from the host star.
It is hypothesized that exoplanets exposed to supernovae and enhanced ultraviolet radiation from their host stars encounter large amounts of nitrogen dioxide in the atmosphere, which in turn leads to the formation of brown haze. According to the NASA report, astronomers are confident that the Earth has also been hit by supernovae in the past. This is confirmed by the finds of radioactive iron in different parts of the planet.
Scientists claim that supernovae could have occurred 65 to 500 light-years from Earth 2 to 8 million years ago. At present, the Earth and the solar system are at a safe distance from potential supernova explosions. However, this does not apply to other exoplanets in the Milky Way, including those in the galactic zone of life, where there should be favorable conditions for the development of life.
According to NASA, Betelgeuse and Antares are the stars closest to Earth and may undergo supernovae in the future. However, this will only happen in a few million years, which gives humanity time to prepare.
See also: scientists believe that artificial intelligence can destroy humanity.
