At the earth’s crust, temperatures remain relatively stable throughout the year. However, under the crust, under our feet is an incredibly hot place – the core of the Earth!
From the management of plate tectonics to our protection against solar radiation, the Earth’s core is not only interesting, but in part vital to life on Earth. But how long can the core of the Earth stay hot?
Read on to find out.
ABOUT IT: A QUESTION TO UNDERSTAND LIFE ON EARTH
How hot is the center of the Earth?
How hot is the Earth’s core?
Experts believe that the Earth’s core exceeds temperatures higher than the sun’s surface – over 18,032 degrees Fahrenheit (10,000 degrees Celsius).
How did it get so hot in the first place?
One theory is that about 4.5 billion years ago, our solar system consisted of a cloud of cold dust particles. This cloud of gas and dust was somehow disturbed and began to collapse, while gravity pulled everything together, forming a huge rotating disk.
The center of the disk gathered to become the Sun, and the particles in the outer rings turned into large balls of fire and molten liquid that cooled and condensed to take on a solid shape.
At the same time, the surface of the newly formed planet was constantly bombarded by large bodies hitting the planet, producing immense heat inside it, melting the cosmic dust found there.
When the Earth was formed, it was a uniform hot stone ball. Radioactive decay and the heat left over from the formation of the planet made this ball even hotter. Finally, after about 500 million years, the Earth’s temperature reached melting point iron – about 1,538 ° Celsius (2,800 ° Fahrenheit).
This allowed the Earth molten, rocky material to move even faster. Relative FLOATING material, such as silicates, water and even air have remained close to those of the planet exterior and would become the early mantle and crust. Drops of iron, nickel and others heavy metals gravity to the center of the Earth, forming the early nucleus. This process is called planetary differentiation.
In contrast to the mineral– rich crust and mantle, it is believed that the core is made almost entirely of metal – specifically, iron and nickel. While the inner core is considered to be a solid ball with a radius around it 1,220 km, with a surface temperature of 5,700 K (5,430 ° C; 9,800 ° F); it is believed that the outer core is a fluid layer approximately 2,400 km (1,500 miles) thick and reaching temperatures between 3,000 K (2,730 ° C; 4,940 ° F) and 8,000 K (7,730 ° C; 13,940 ° F).
It is believed that the core is so hot because of the decay of radioactive elements, the heat remaining from the planetary formation and the heat released as the outer liquid core solidifies in its vicinity limitation with the inner core.
So the core is incredibly hot, but how much longer can it stay hot?
Scientists at the University of Maryland say they will be able to answer the question in the next four years.
Leading the movement of the Earth’s tectonic plate and feeding its magnetic field requires a huge amount of power. Energy is derived from the center of the Earth, but scientists are sure that the core cools very, very slowly.
What makes the center of the Earth hot?
Keeping the Earth’s center hot are two sources of “fuel”: the primary energy left over from the formation of the planet and the nuclear energy that exists due to natural radioactive degradation.
The formation of the Earth came at a time when the solar system was full of energy. During his childhood, meteorites constantly bombarded the forming planet, causing excessive amounts of frictional force. At that time, the Earth was full of volcanic activity.
How long will the Earth’s core last?
From the beginning, the planet has cooled significantly. However, the residual heat from the formation of the Earth remains. Although the primordial heat has largely dissipated, another form of heat continues to heat the Earth’s mantle and crust.
Naturally, radioactive materials exist in large quantities deep in the Earth, some of them living around the crust. During the natural process of degradation of radioactive material, heat is released.
Scientists know that heat flows from inside the Earth into space at a rate of about 44 × 1012 W (TW). However, what I don’t know is how much heat is paramount.
The problem is that if the Earth’s heat is predominantly primordial, then it will cool much faster. However, if the heat is created largely due to radioactive degradation, then the Earth’s heat is likely to last much longer.
Although it sounds quite alarming, I see some estimates for the cooling of the Earth’s core taking it tens of billions of years, or even 91 billion years. This is a very long time and in fact the Sun will probably burn long before the nucleus – around 5 billion years.
Why is the Earth’s central temperature important?
The Earth’s core keeps the temperature stable, but more importantly, it keeps the Earth’s magnetic field in place. The Earth’s magnetic field is created by the motion of the outer core of the molten metal.
This massive magnetic field expands into space and holds charged particles in place, which are collected largely by solar winds.
Fields create an impenetrable barrier in space that prevents the fastest and most energetic electrons from reaching Earth. The fields are known as the Van Allen belts and are the ones that allow life to thrive on the Earth’s surface. Without the shield of the magnetic field, the solar wind would remove the Earth’s atmosphere ozone layer which protects life from harmful ultraviolet radiation.
The collection of charged particles deflects and captures the solar wind, preventing it from removing the Earth from its atmosphere. Without it, our planet would be barren and lifeless. It is believed that Mars once had a Van Allen belt that also protected it from the deadly wind of the Sun. However, once the core has cooled, it has lost its shield and now remains a desolate wasteland.
How long will the Earth’s fuel last?
Today, many scientific models can estimate how much fuel is left to drive Earth’s engines. However, the results differ greatly, making it difficult to draw a final conclusion. At present, it is not known how much primordial and radioactive energy remains.
“I’m one of those scientists who created a compositional model of the Earth and predicted the amount of fuel on Earth today,” said one of the study’s authors, William McDonough, a professor of geology at the University of Maryland.
“We are in an area of assumptions. At this point in my career, I don’t care if I’m right or wrong, I just want to know the answer. “However, researchers believe that with modern technological advances, a more accurate prediction can be made.
To determine how much nuclear fuel remains on Earth, researchers use advanced sensors to detect some of the smallest subatomic particles known to science – geoneutrinos. Geoneutrino particles are the by-products generated by nuclear reactions that take place in stars, supernatants, black holes and man-made nuclear reactors.
Detection of the remaining fuel
Detecting antineutrino particles is an extremely difficult task. Massive detectors the size of a small office building are buried less than 0.6 miles (one kilometer) in the earth’s crust. The depth may seem exaggerated; however, it is necessary to create a shield against cosmic rays that can lead to positive fakes.
In operation, the detector can detect antineutrinos when they collide with hydrogen atoms inside the device. After the collision, two bright flashes can be detected, which unequivocally announce the event.
By counting the number of collisions, scientists can determine the number of uranium and thorium atoms that remain inside our planet.
Unfortunately, the KamLAND detectors in Japan and the Borexino in Italy detect only about 16 events a year, which makes the process slow. However, with three new detectors projected to be online in 2020 – Canada’s SNO + detector and China’s Jinping and JUNO detectors – researchers expect more than Another 500 events detected per year.
“Once we collect three years of antineutrino data from all five detectors, we are confident that we will have developed an accurate fuel indicator for the Earth and will be able to calculate the amount of fuel left on Earth,” McDonough said.
China’s Jinping detector is over four times larger than all detectors so far. Although the detector is large, the JUNO detector will be amazing 20 times larger than all existing detectors.
“Knowing the exact amount of radioactive energy on Earth will tell us about the Earth’s past consumption rate and its future fuel budget,” McDonough said.
“By showing how quickly the planet has cooled since birth, we can estimate how long this fuel will last.”
When JUNO goes online; hopefully by 2021 – the data collected should help scientists like McDonough estimate the time left to cool the Earth’s core. Until then, rest assured that any estimates will likely reach hundreds of millions, perhaps billions, of years in the future.
So you don’t need to make plans to move to a new planet soon.