Many of us remember from childhood the mnemonic memory "We'll Meet Tomorrow, My Young Satellite, At the New Planet", with which you can easily determine the places of the planets in the solar system. In school, we learned that the Earth revolves around the Sun, the Sun is a hot ball of gas, and we live in the Milky Way galaxy. Some of us know well the constellations of the sky or the phases of the moon. However, the day will come and the cosmos will change. Some of the changes will bring much more than just removing Pluto from the planetary list. Whether it is total annihilation or simply lighting up our skies, these changes will come and affect the Earth. So get ready.
From the death of the sun
Stars are like living things: they are born, live and then die. Our Sun is no exception. One day, at least 5 billion years later, our precious Sun will die, and this will have to be accepted as a fact.
A star dies when it runs out of fuel. During the life of stars, nuclear fusion takes place in them. The star takes hydrogen from its core, heats it to extreme temperatures and turns it into helium. Then, when the star uses up all of its hydrogen, it becomes a red giant. The outer layers cool and expand, and the core, now made of helium, heats up and burns the helium into carbon. From this point on, the process can proceed in several different ways. If it is a very massive star, the process of thermonuclear fusion will continue, fusing heavier elements until it reaches iron and explodes in a supernova. A supernova will leave behind a neutron star or black hole.
Stars of lesser mass, like our Sun, will take a less dramatic path. They will expand into red giants, but not explode, but eject the outer layers, leaving bare cores. We call these remnants white dwarfs.
The consequences of the death of the Sun will simply incinerate the Earth. Despite the fact that the Sun will not explode like a giant firecracker, the expansion will simply “eat up” Mercury, Venus and Earth. When the Earth hits the hot, expanding layers of the Sun, several things will happen. First, all bodies of water will evaporate and break down into its constituent water, hydrogen and oxygen. Hydrogen will be lost in the atmosphere and oxygen in the earth. Secondly, our atmosphere will change a lot. It will be composed mostly of nitrogen and carbon dioxide. These two effects will render the planet uninhabitable. In short, when the Sun dies, we will die too, if we do not fly away in time.
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Collision of galaxies
Before we start worrying about the death of the Sun, we have something else. Our home, the Milky Way, will not always be our home. In 4 billion years, even before the death of the Sun, the galaxy will collide with the nearest spiral galaxy Andromeda.
Scientists learned about this when they measured the speed of Andromeda and realized that instead of redshift, or moving away from us, as predicted, the galaxy passes through blue shift. These colors correspond to the wavelengths of light that is emitted from an object. As an object moves away from us, the wavelengths of its light become longer and the light itself becomes redder. Blue shift is exactly the opposite: as an object approaches, the wavelengths of its light are compressed. Further measurements and calculations allowed scientists to determine the size, movement and speed of Andromeda. It turns out that the Milky Way and Andromeda are approaching at a tremendous speed: 402,000 kilometers per hour.
As for the solar system, there is nothing to worry about. The chances that our solar system and the sun will be thrown out or destroyed are very small, since the collision of galaxies is not like the collision we are used to. It's not like two cars collided head-on. The two galaxies will spiral into each other, like animals in a mating dance, coming closer and closer. During this dance, the edges of galaxies will be the first to touch. Certain disturbances will follow, but changes in the solar system and the sun will be almost imperceptible. In the last stages of merging, all stars will begin to belong to one of the gravitational centers. Finally, the two supermassive black holes at the center of each galaxy will merge, engulfing the surrounding matter. The stars surrounding the new center, including the Sun, will be pushed out and form an elliptical galaxy.
Since the Earth will survive and the Sun will not die yet, future earthlings will be able to witness this incredible event. Add yourself to your calendar.
Betelgeuse explosion
This item on our list is not catastrophic and will not have a serious impact on the universe. However, it will completely change our night sky and make many prying eyes cling to the eyes of telescopes.
Betelgeuse is a red giant with a reddish glow visible in the northern hemisphere. He is in the constellation Orion and is his "right hand", so for observers, the star will be on the left in the massive constellation, just above the belt.
Unlike our sun, Betelgeuse is a massive star that is living out the last days of its life. As a red giant, it burns helium in its shell and carbon along with other heavy elements in its core. One day this star will explode into a supernova. It can happen literally any minute, so don't miss it.
Betelgeuse, a member of the Milky Way, has already become the ninth brightest star in our sky, so when it explodes, it will be comparable in brightness to the Moon. The night will not only become as bright as day, but it will also be possible to observe it during the day. The supernova will be visible for several weeks while the object expands, reaches a maximum luminosity, and then fades out again.
There has been no supernova in the Milky Way since 1604. Then the scientist Johannes Kepler saw a supernova, which would later be named after him. The last time a supernova of significant brightness was visible to us from Earth was in 1987. Supernova 1987a disappeared in the Large Magellanic Cloud, one of the Milky Way's galactic neighbors. There have been many supernovae since then, but only a 1600s supernova was evident. It was visible only in the southern hemisphere, although in terms of brightness it was not the same as Betelgeuse would be.
Expansion of the solar system
If you thought it was difficult to remember the order of eight or nine planets as a child, add another hundred.
Yes, there can be more than a hundred objects in the solar system. This does not mean that more than a hundred planets will be discovered, but the definition of planets may change to include more than a hundred other bodies, such as the Moon and Pluto. Earlier this year, scientists began arguing about what defines the planet, and, as always, the controversy flared up in earnest.
The modern definition of a planet implies a body with powerful gravity and its own possession. For example, the Earth is a planet because it is large and has its own gravitational territory. The moon, which hundreds of years ago was considered a planet, is not a planet today, since it revolves around the Earth, being secondary to it. This definition was put forward in 2006 and ultimately demoted Pluto in rank. This year a "new" definition was proposed, less about gravity and more about the composition of the planet. According to it, a planet is any body that is massive enough to have its own gravity, but not massive enough to start nuclear fusion and burn like a star. By this definition, the planets will be the Moon, Pluto's moons, Pluto itself and other objects in the Kuiper belt.
While this definition does not have any physical effect on the Earth, it is very important. Just imagine how many objects children will have to memorize in schools if the list of the family of our solar system includes hundreds of them.
Planet Nine - Again
Instead of adding a hundred planets, scientists from California announced last year the possible discovery of a "ninth" planet behind Neptune. This gigantic ice body should be ten times the size of Earth and have a powerful gravitational field. Therefore, it will fit into the modern definition of gravitational dominance, as well as into the "new" definition of composition.
The only but: scientists have not yet seen this planet. They don't even know for sure if it exists, but everything speaks in favor of it. It's all about the behavior of the bodies surrounding this planet. The orbits of distant objects behave as if they are being influenced by an invisible force. This invisible force could very well be a planet. So far, two telescopes are looking for it. The further away an object is, the more difficult it is for the light of the Sun to reach it, so the planet will be very dark.
If a planet is found - and if it is a planet - it will completely change the way we think about the solar system.
Moon Departure
The moon, the eternal companion of the Earth, which has been nearby for billions of years, is gradually moving away from the Earth - about 1.48 inches per year. This is due to the action of tidal forces. The gravitational and tidal forces that the Moon and Earth exert on each other cause friction. This friction pushes the Earth's tides towards the Moon. This push tries to accelerate the Moon, but is balanced instead. The moon gradually loses energy and slows down in orbit, gradually floating away.
This small change could have many important consequences for the Earth and for us. For example, the length of the day will change. When the Moon and Earth first formed 4.5 billion years ago, the days were only 5 hours long. Each year, the day increased by 0.0000152 seconds. In 250,000,000 years, there will be 25 hours in a day. Great news for those who can't get everything done in a day, but not so much for the environment.
Slowing down the speed of the Earth's rotation will wobble it like a slowing top wobbles. This wobbling will greatly affect the seasons, lead to powerful jumps in temperature, and kill many plants and animals that do not have time to adapt. However, people have nothing to worry about.
Martian rings
Again, this is not the most catastrophic, but very beautiful change. It will simply be inevitable, like the explosion of Betelgeuse, and we will see it in the sky.
It is unlikely that we will see this with the naked eye, but in 70 million years, Mars will have rings. One of the Martian moons Phobos is moving towards the Red Planet. Once it reaches a certain point, the gravity of Mars will take its toll and tear the moon apart. The debris will be captured in orbit and will begin to circle the planet, forming rings.
While this won't affect Earth much, it's a good reason to uncover your telescope.
Destruction of the solar system
There is a small but tangible chance that the orbits of the four inner planets will become completely chaotic and lead to devastating collisions. Everything will start from the orbit of Mercury. First, its orbit around the Sun will become a more eccentric ellipse. That is, it will stretch. Second, the precession will change too. Orbital eccentricity is a very important parameter. Scientists have found that Jupiter's gravity could grab Mercury and pull the planet out, potentially intercepting Venus. Another possible scenario could be this: Mercury will go beyond the orbit of Venus and collide with the Earth. If the former happens, the Earth may be fine. If the latter, we will die.
But don't panic. While these scenarios cannot be discounted, the chances of any one of them coming to fruition are very small. Be that as it may, we will have three billion years to prepare.
The core of the earth will cool down
The Earth is very hot, but its molten core is cooling down, and when it reaches a certain temperature, the planet will no longer be.
Currently, the core is simultaneously freezing and melting. As the core begins to cool and freeze, it releases heat energy into the metal-rich region between the core and the earth's crust called the mantle. This creates convection in the mantle as heat rises and cold falls. Currents move magnetic iron, creating the earth's magnetic field. Although this is a "normal" process, in some places along the core-mantle line, the energy of the mantle returns to the core, and these spots melt.
We see that the core simultaneously loses and gains heat, but if the core simply cools down completely, the effects will be devastating. The greatest effect awaits our protective magnetic field. If the core freezes, convection stops and the magnetic field stops being generated. Everyone knows that the magnetic field protects the Earth from the dangers of space. Without it, the planet will be open to radioactive waves and scorching solar winds.
While this is unlikely to happen, it should not be completely ruled out. Sometimes it's better to just not know what's going to happen.
The Great Divide
This scenario is also hypothetical, like the cooling of the Earth's core, but is associated with a phenomenon that occurs periodically. Scientists have proven that the universe is expanding and accelerating. The accelerated expansion of the Universe is fully justified by mathematical predictions, and one of the outcomes of this expansion sheds light on a not very pleasant fate.
The so-called Big Rip will be the opposite of the Big Bang. During the Big Bang, the universe and everything else was formed. The Great Rip will be akin to the destruction of everything created. According to the theory, the faster the expansion, the stronger the dark energy will be. One day the force of dark energy will reach a point after which other objects and forces will not be able to resist it and will be torn to pieces.
Including us.
ILYA KHEL