Gamma Ray Burst.
Writing the previous article about the spectrum of light, my attention drawn gamma radiation, and more precisely the derivative of the name appearing in another phenomenon. And by that I mean Gamma Ray Burst.
The most powerful space explosions called Gamma Ray Bursts are a constant threat to life on Earth. Imagine that you can collect energy from every star within a hundred million light years and use it to launch the largest super weapon in the universe. In short that what this phenomenon is. According to one hypothesis, this phenomenon is responsible for the massive extinction on Earth which occurred about 450 million years ago. Luckily, no gamma burst has occurred in our area since then, but this day will inevitably come.
Gamma rays are electromagnetic radiation waves which carry energy just like visible light. Visible light is a tiny part of the electromagnetic spectrum. It's the part your eyes can see. At lower energies, there are radio waves, microwaves and infrared. And at higher energies are ultraviolet, x-rays and gamma rays.
Gamma rays have the smallest wave lengths due the fact that they are the highest energy photons. Gamma radiation is extracted from radioactive elements, unseen parts of nuclear reactors. It penetrates quite well through hard matter. In excess, this radiation can cause radiation sickness or be lethal to tissues.
In front of the gamma radiation that reaches the Earth from space, the Earth's ozone layer protects us. The existence of phenomena such as gamma-ray bursts were not known until the second half of the twentieth century. This phenomenon was detected by chance due to the "Cold War". The Americans simply placed a special satellite in orbit around the planet, whose task was to track by means of on-board equipment that USSR does not carry out trial nuclear explosions in outer space. Instead, an unknown type of more powerful space explosion was discovered.
Since then, hundreds of bursts have been observed, but fortunately, all occurred far enough that they did not pose a threat to us. However, if a huge amount of gamma radiation reached us, it would mean great trouble. Gamma radiation breaks down ozone, so this emission would deprive us of a protective ozone layer. This means that not only the gamma-ray burst would be a disaster, but also its effect would be to open the path to the surface of the Earth for Sun's UV radiation.
Gamma Ray Bursts are releasing more energy in a second than the sun will, in its entire ten-billion-year lifetime. Making them, the brightest events in the universe. There are two types of Gamma Ray Bursts short and long, and each has their own source. Long bursts last about a minute, and scientist think they are produced by Supernova when the core of a massive star collapses to become a Black Hole. Short bursts last a second, and are produced when two Neutron Stars are in a binary merge. Over millions of years, their orbits decay by emitting gravitational waves.
Once they are close enough to touch, they crash and splash into each other, forming a Black Hole. Both Supernova and Neutron Star mergers the same thing: Black Holes, surrounded by a magnetized disc of gas left over from their parent stars. In these environments, the rotation winds up the magnetic field, which funnels hot jets of particles, traveling at nearly the speed of light. The gas in this funnel creates two tight jets of high energy gamma rays, like a celestial laser gun.
All the bursts we have detected so far, originated outside the Milky Way, too far away to hurt us. But a nearby Gamma ray burst could be disastrous, if one goes off within a few light years of us, it would totally cook the surface of the Earth. Or at least, the half that's facing it.
The ozone layer protects us, but it's better equipped to handle the trickle of ultraviolet from the sun. A Gamma Ray Burst would overwhelm it, leaving us exposed to deadly solar radiation. Ozone takes years to replenish itself by natural processes, which is more than enough time for the sun to burn the Earth sterile. Or at least, to kill most complex life.
A massive star sinking into a black hole.
Scientists some time ago proposed a hypothesis that the huge extinction on Earth, which occurred 450 million years ago was caused by a nearby Gamma Ray Burst. As a result, 60% of animal species disappeared from the Earth's surface. Until now, considered reason for the extinction in this period was the beginning of the ice age. Unfortunately, science does not have any information about whether or not we are threatened by a Gamma Ray Burst.
If a Gamma Ray Burst occurs in our galaxy, we will talk about a likely natural disaster. However, if its source is less than 6,000 light years from Earth, the planet is in danger of complete devastation.
References:
[1]http://regulus.wis.pk.edu.pl/Odczyty/Prelekcje/gamma.pdf
[2]https://www.ifj.edu.pl/conf/AstroCzastki2013/prezentacje/A_Zwolinska_poster.pdf
[3]http://www.urania.edu.pl/tagi/rozblyski-gamma
[4]https://zmianynaziemi.pl/kategoria/rozblysk-gamma
[5]https://pl.wikipedia.org/wiki/Rozb%C5%82ysk_gamma
[6]https://zmianynaziemi.pl/wiadomosc/rozblysk-gamma-moze-w-kazdej-chwili-zniszczyc-zycie-na-ziemi