the birth of our planet

Stardust: Stars shed their outer layers towards the end of their lives. The massive stars that can no longer support their own weight and sink into themselves, originating the supernova explosion that scatter their ashes in the form of great clouds of dust and molecules. From one of these clouds our solar system was formed. Each molecule of our organism contains elements that were cooked in the stars. Each gold atom of the covenant that many carry on the finger was generated in a supernova.

The presence of decay products of short-lived radioactive isotopes in ancient meteorites indicates that these elements originated in the explosion of a nearby supernova. What's more, it may have been one of those explosions that triggered the initial collapse of the solar nebula

Accretion: As the gas and dust were concentrated in the center, where they would end up forming the sun, the angular momentum of the slowly rotating nebula was placing the material in a kind of flat disk. For a long time, this was only a theory, but today's powerful telescopes allowed us to see how it is happening in other Star incubators.

For example, the star Beta pictoris is surrounded by a disk of dust and clearly visible stone grains that may be forming planets at this precise moment. The discovery of so-called exoplanets around more than a thousand other stars indicates that planetary formation often accompanies the birth of a star.

It is a generally accepted thesis that the planets of our solar system formed in a process called accretion, in which small grains of matter collide with each other and come together. The first part of this process is the most difficult to understand, since the force of gravity would be very small and could hardly keep the clumps together, apart from the fact that the collisions normally fragmented again. It is possible that the grain concentrations behave in the same way as the kinetic liquid, which stays together and only occasionally gathers enough energy to splash out of the agglomerate. If the relative speeds of the grains were sufficiently low, it would begin to gather, and once the size of a few meters in diameter was reached, the force of gravity would assume the task, attracting and gathering more and more the material.

Separation: The gravitational energy, the heat of the radioactive decay and the energy released by the impacts of the collisions surely caused the materials to melt, which finally allowed the heavier elements, such as iron and nickel, to come together in a nucleus inside a body that would then be more or less spherical and maybe you would tell me hundreds of kilometers in diameter. This body would continue to agglomerate the rest of dust and larger fragments to form a smaller number of proto-planets. The collisions between them must have been less frequent, but more violent.

The solar wind: Probably the sun was formed in only about 10,000 years, at the end of which sufficient material had been collected to reach the temperatures necessary to initiate nuclear fusion and for the sun to shine. This generated a strong solar wind of particles that blanketed the entire young solar system and carried away any early atmosphere of hydrogen and helium from Earth, leaving only the toughest rocks on the planet. The bulk of the gas symptoms towards the outside of the solar system, where the giants that are gaseous planets, jupiter and Saturn were formed. Volatile materials, such as methane and water, reward even more to the outside, forming ice bodies from the confines of the solar system: dwarf planets such as Pluto, ice moon, kuiper belt objects and comets.

A new planet called earth: Our young earth continued to grow. The interior is probably fused for the most part, with an iron core surrounded by the primitive mantle of silicate. Once acquired about 40% of its current mass, the force of gravity would have helped it retain an atmosphere, while the magnetic field generated by the iron core would have protected it by diverting solar particles. This first atmosphere was probably formed by Nitrogen, carbon dioxide and water vapor.

The accretion process continued, culminating in the great impact that gave rise to the moon. As the earth is cool, it is possible that there was liquid water on the surface. Some of the water vapor may have generated on the planet in the form of volcanic gases, but it is likely that much of it will come to earth with The Ice Comets, along with the rocky material that meteorites and asteroids. This accretion process is still ongoing, although on a smaller scale. If we go outdoors in a dark night with clear skies, we may see a shooting star. These are small grains of solid matter that burn when entering the atmosphere, but eventually land on the surface. They are not bigger than a grain of water at most grain of rice, but between all they contribute 40,000 tons every year, giving continuity to the process in which our planet was born.