Billions of years ago, when the big bang took place, this universe and the earth were formed. Ever since then different organisms have lived and are still living on this earth. It's believed that the life of dinosaurs came to an end when a meteorite from outer space crashed into the earth. That led to the extinction of dinosaurs. Apart from nuclear wars, large-scale pandemics and global warming, disasters from space can also end life on earth. Let us learn about the asteroids, meteorites, cosmic disasters that can end life on earth, and disasters from space below.
The sun may look peaceful and quiet but it is not. The sun generates strong magnetic fields and these can generate sunspots. These spots can be small and sometimes they can be even larger than the earth. Solar flares or solar winds are the streams of particles and radiation that are ejected by the sun. The northern and southern hemisphere lights are caused by these winds only. A stronger wind and storms from the sun can even cause disturbances in radio signals and can cause power outages. In 1859, one of the most powerful solar storms occurred. It is known as the Carrington Event. These solar winds mainly affect electronic equipment and in today's world, we have become very much dependent on them. So if more powerful storms occur, they can not only affect the electrical system but also end our lives. No electricity would be there so no internet, food, or anything.
These are some of the major disasters from space. The asteroids impose a very big threat to humanity. As we read above that the studies suggest, they were the reason for the extinction of dinosaurs. These are space rocks present in our solar system and can come to earth anytime. We have started developing systems to counter these small asteroids, but we still need to work on how to tackle the larger asteroids. These asteroids can wipe out humans by causing high tsunamis, fires, and other natural disasters that can end the lives on earth.
[Image: Schematic view of an asteroid]
The above two disasters occur at a roll of a dice but for this one, we know that the sun will end its life in 7.72 billion years. The outer atmosphere of the sun will be thrown away to form a planetary nebula and then it will be converted to a white dwarf. But our humanity won't be able to witness all these events because as the sun will reach its final stages, it will become cooler and larger. This large area of the sun will be responsible for engulfing the mercury and the venus. But later on as this proceeds, the sun will create strong solar winds that will slow down the earth. So in about 7.59 billion years our earth will melt away and die.
Gamma rays are released from the sun. They are extremely powerful outbursts of energy. These bursts can be caused by binary star systems and supernovas. The supernovas are exploding stars. The energy of these bursts is focused on narrow beams and these beams can last no longer than seconds. These beams can thus damage our ozone layer and when the ozone layer is destroyed, it can cause humans to suffer from UV radiation. These radiations can cause skin cancers and other diseases in human beings. A star named WR 104 has been discovered by astronomers and this star can cause such an event.
When a star reaches its end, it bursts and this is known as a supernova. On average, it occurs every hundred years in our milky way galaxy. Recent studies have shown that there is a star named Betelgeuse. It is a red supergiant that is about to receive its ends. So in the next million years, this star can become a supernova and cause destruction to our planet. It is 460-500 light-years away.
Our milky way galaxy is made up of millions and billions of stars. Anytime a small or big moving star can come in close vicinity to the earth and cause destruction. The stars can come in contact with the Oort clouds that are present at the end of the solar system and it can lead to a huge chance of a comet reaching and destroying earth anytime. But to protect us from this, the sun’s wind and its magnetic field help create a bubble around the solar system that protects us from these moving stars.
Well, everything that has taken birth has to come to an end one day or another. We can conclude from the above paragraphs that our earth is very vulnerable to all these disasters but we cannot just sit back and wait for them to happen. We are making advancements in our studies and learning new techniques to protect our earth. The above discussed are some of the cosmic disasters that can end life on earth.
1. What is the Ozone Layer?
Answer: It is also known as the ozone shield and is present in the stratosphere. The main function of ozone is to absorb ultraviolet lights and protect us from them. It contains a high concentration of ozone molecules. This layer was discovered by Fabry and Buisson. If the ozone layer is not present then the harmful ultraviolet lights from the sun would penetrate our earth and long exposures to these lights can cause skin cancers and various other diseases to human beings.
2. What is a Nebula?
Answer: It is basically a cloud of dust, helium, hydrogen, and other gases. The Andromeda Galaxy is referred to as the Andromeda Nebula (and spiral galaxies in general as "spiral nebulae"). Most nebulae are of vast size and they are hundreds of light-years in diameter. A nebula that is visible to the human eye from Earth would appear larger, but not brighter. The Orion Nebula, the brightest nebula in the sky and occupying an area twice the angular diameter of the Full Moon, can be viewed with the naked eye. Although denser than the space surrounding them, most nebulae are far less dense than any vacuum created on Earth. Many nebulae are visible due to fluorescence caused by embedded hot stars, while others are so diffused that they can be detected only with long exposures and special filters.