The observable universe is 93 billion light years old, but Earth is the only planet known to harbor life.
The Earth has the right temperature, reasonable day and night alternation, sufficient water resources. These conditions gave birth to all things on Earth, and the Earth can have these thanks to its unique geographical location:
The Earth is at just the right distance from the sun. If it were closer, it would be covered in lava, like Venus, at an average temperature of 400 ° C, or farther away, like Mars, where the temperature difference between day and night can reach about 100 ° C.
But observations show that the distance between the sun and the Earth is not constant, which means that the Earth may one day move further and further away from the sun, becoming a cold world, or closer and closer to becoming a melting pot.
Having a stable star is a necessary condition for life on a planet. If the parent star is a low-mass red dwarf, it will regularly erupt in massive solar storms, and the surrounding planet will be bombarded with radiation so intense that it will be difficult for an atmosphere and liquid water to exist on its surface 39bet-xsmb-xổ số tây ninh-xổ số binh phước-xổ số binh dương-xổ số đồng nai.
Or the parent star is stable, but unfortunately there are three parent stars in this galaxy. Then the three stars would move in a trisomy with unpredictable trajectories, tossing the stars around, alternating between freezing and melting POTS, and not being able to live for long.
Although stars appear to be immutable, hanging steadily in the sky, in fact stars are born and die. In the case of the sun, the solar system began as a primitive nebula left over from a supernova explosion, where some of the larger molecules, gravitationally disturbed, began to attract surrounding matter towards them.
As the center becomes denser and denser, more atoms fall, eventually causing the temperature and pressure inside to rise rapidly. Along with the compression process, the molecular cloud spins faster and faster. When the temperature and pressure reach a threshold, the hydrogen atoms begin to fuse, and the sun is formed.
The Sun's ability to radiate light and heat is due to the continuous fusion of hydrogen and helium inside the sun, which makes up 99.8 percent of the solar system's total mass. Hydrogen fuels the fusion, making up three-quarters of the sun's mass, with the rest being fused helium.
The sun emits 36 petajoules of energy per second, enough to power humans for more than 700,000 years, but because of distance and the atmosphere, that energy actually reaches only about 2.2 billionths of what it used to on Earth, but only a billionth of that, enough for life to thrive on the entire planet.
The energy released by the sun is so great that it consumes four million tons of its mass every second. Four million tons may seem small compared to the sun, but over the sun's remaining five billion years, it will lose 0.1% of its mass, a small amount but a large amount, equivalent to the mass of a Jupiter.
According to the law of universal gravitation, the quality of an object is directly proportional to its gravity, the greater the quality, the greater the gravity, and the sun constantly fusion slowly reduces its quality, leading to the gravitational pull of the sun on the surrounding material becoming more and more small, when gravity source quality constantly attenuation, to maintain the radius of the orbit earth will follow.
This means that the Earth will move further and further away from the sun. Scientists calculate that the distance between the Earth and the sun increases by about six centimeters per year, regardless of other factors, based on the loss of the sun's mass.
So what will be the impact of the sun's continued retreat on Earth and humans?
The first is that the temperature of the Earth will decrease because the distance between the sun and the Earth will decrease, and the amount of light and heat from the sun reaching the Earth will decrease. The second is that in the next few billion years, the sun will appear dimmer and dimmer when viewed from the Earth, and the days will not be as bright as they are now.
But if the sun is moving away from Earth, why do we still feel hotter every year?
In fact, with the increase of distance from the sun and the earth, the temperature of the earth does decrease, but the change is too small, even negligible, only after the time to be stretched, we can observe the obvious changes in the earth's temperature, and the mass of the sun is more and more small, besides can reduce their gravitation, also will enhance the strength of the internal fusion.
And because compared with cool, the sun's nuclear fusion strength increase caused by temperature effect is far greater than the former, scientists predict that the future of the sun every 1 billion years, the brightness will increase about 6%, make the earth's surface temperature increased, until the final boiling sea, that is to say, the day before the sun into a red giant, the earth is no longer suitable for human habitation.
Even if the Earth doesn't warm up too much to be habitable, it will still be swallowed by the Sun after it expands into a red giant, but there's disagreement about how far the edge of the sun's orbit will go when it becomes a red giant, and a few people think the Earth might still be able to stay in its old orbit.
But by then, Earth would be uninhabitable, and humans would probably have mastered interstellar migration and found a new home in outer space.