The Stages Of The Formation Of The Earth

Five billion years ago, the Earth did not exist. On the outskirts of our galaxy, the Milky Way, there was only a vast cloud of gas and dust. At the origin of this cloud: the explosion of a supernova.

Through What Process Did Dust Turn Into A Planet?

In March 2003, an informal experiment carried out by astronaut Donald Pettit in the International Space Station shed light on this process. This astronaut amused himself by observing bags containing salt in zero gravity. The interest of D. Pettit’s observation was revealed by another astronaut: Stanley Love.

At the origin of this reduction: radiation consisting of hot hydrogen (a similar phenomenon is at the origin of the formation of enstatite chondrites (models for the formation of the Earth), radiation corresponding to the T Tauri phase of the Sun (radiance of a young star observed for the first time in the constellation Taurus).

The Earth, Therefore, Cooled Down To Reach A Temperature Of 1100 ° C.

When the Earth is about 50 million years old, it will collide with another protoplanet (the size of Mars). This collision will be such that the Earth will “melt.” This collision would be at the origin of “the ejection of the Moon.” The Moon would have formed by agglomeration of rock residues vaporized during the impact. Check for

Initially, the Moon was much closer to the Earth than today, and its presence generated the tides. The collision probably modified the axis of rotation of the Earth, and this inclination is at the origin of the seasons.

The impact that gave birth to the Moon would also have determined the differentiation of the Earth and its organization in several layers. The two objects that collided already had a core each. During the shock, the two nuclei would have merged and given a single nucleus. The Earth’s surface would have remained molten for thousands of years following the impact, forming a “magmatic ocean” at least 1,000 km deep.

The fusion of the silicates produced magma depleted in silicon. The denser silicate residual solids formed the lower mantle. The even denser liquid iron/nickel alloy has migrated towards the center, reducing some of the silicon silicates in its path, incorporating this silicon as well as oxygen. This migration (in less than

During the melting of the upper mantle, almost all of the gases escaped, contributing to the formation of the atmosphere.

At the end of this primitive differentiation, 4535 million years ago, the Earth was made up of a liquid core about 3400 km in diameter, a lower mantle (1900 km thick), and d ‘an upper mantle (magmatic ocean about 1000 km thick).

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