Age of our planet

If you imagine the entire history of the world as one day, people only appear in the last seconds before midnight. Our species’ few hundred thousand years are only a small fraction of our planet’s history, he writes 24 Channels.

The world was formed about 4.54 billion years agoAbout 10 million years after the birth of the Sun. After the huge gas cloud collapsed and formed our star, the remnants of that cloud began to form planets along with the dust. Scientists say that 99% of all material went into the formation of the Sun, and only 1% went into forming all other bodies in the Solar System.

At the beginning of its life, the Earth looked nothing like the lush, green world we know today. When it was formed, it had melted for a long time due to collisions with many cosmic rocks. They came together, stuck together, attracted others, and thus increased in size and mass. Heavier pieces of material, such as iron, sank deeper to form the core, while lighter elements rose to the surface. Ultimately, this led to the formation of a layered Earth consisting of a core, mantle, and crust.

When the solar system calmed down and fewer asteroids began hitting Earth, oceans formed and life began almost immediately. Although humans will not have existed for most of Earth’s history, cellular life has a continuous streak of about 3.5 billion years, and new research suggests that number may be even longer, at 4.2 billion years.

How did we learn this?

Scientists owe this knowledge to the Earth itself. Rocks are key to determining a planet’s age and what it was like in the past. through a process known as radiometric datingScientists can use the amounts of different radioactive elements to determine the age of a rock.

However, studying rocks on Earth can be very difficult, as geological processes such as volcanoes, weathering and the subduction of lithospheric plates mean that it is difficult to find rocks from the time when the Earth formed. Scientists managed to find minerals reaching an age of 4.4 billion yearsThis means that the planet has existed for at least that long. So where did the more than 100 million years for which we have no direct evidence go? Why do scientists say the Earth is older?

Mars and the Moon come to our aid here:

• The currently dominant formation theory says that our satellite arose as a result of a collision between the Earth and another giant object at the beginning of the planet’s existence. The second object broke apart, partly remaining in space (and later forming the Moon), and partly joining the Earth’s matter. There are even studies that claim to have found remnants of this ancient impact deep within the Earth. Since there is no plate tectonics on our Moon, rock samples found on its surface 4 billion years ago still exist. Lunar rock samples from the era of the Apollo missions have helped clarify the age of our planet, and new samples from missions like Chang’e 5 have further deepened our understanding of history.
• As for Mars, we have examples of meteors flying from the Red Planet. Their age is 4.5 billion years.
• Additionally, some meteorites that come to us from other parts of the solar system contain material older than 4.56 billion years.

For this reason, scientists call this period when the first rocky formations appear after the birth of stars, the moment of planet formation.