How did the planets of the solar system form? According to the leading theory known as the "protoplanetary hypothesis", small objects in space collided with each other, resulting in their merger. This is how major planets were formed, including gas giants such as Jupiter. But how did this happen ?! Let's figure it out.
The birth of the sun
If you believe this theory, about 4.6 billion years ago on the site of today's solar system there was nothing but free accumulations of gas and dust. These are nebulae known to us. One example is the Orion Nebula, which you can observe in the night sky.
Then, the scientists say, something happened that caused a change in pressure at the center of the cloud. Perhaps the cause was a nearby supernova explosion or a change in the force of gravity of a passing star. One way or another, according to NASA, the cloud "crumbled", and a disk formed from matter.
The pressure in the center of the disk has increased so much that the hydrogen atoms, which previously moved freely in the cloud, began to contact each other. Eventually, this interaction led to their fusion and the formation of helium. This is what prompted the formation of the Sun.
The sun was like a hungry baby and absorbed up to 99% of what was around it. However, there was still 1% matter left. It was here that the process of planetary formation began.
Promotional video:
Chaos time
At that time, the solar system was, as they say, in disarray. But the planets formed relatively quickly. Gas and fine dust particles began to collect in clumps. The young Sun pushed most of the gas into the margins of the solar system. The heat emanating from it was enough to evaporate any ice that was nearby. Over time, planets have formed: rocky bodies are located closer to the Sun, and gas giants - farther from it.
However, about four billion years ago, as a result of an event called by scientists "late heavy bombardment", small bodies fell on large objects in the solar system. According to the theory, the Earth was almost destroyed after it was hit by an object comparable to Mars.
The reasons for this "bombing" still remain a mystery, however, according to some scientists, this is due to the fact that gas giants, moving around small bodies on the periphery of the solar system, "disturbed" them. Whatever the reason, in simple terms, the merger of protoplanets ultimately led to the formation of planets.
The processes of formation of planets in the solar system cannot be considered completely completed. Between Mars and Jupiter is an asteroid belt that could have merged into planets if Jupiter's gravity was not so strong. In addition, there are many comets and asteroids that are sometimes referred to as the “building blocks” of our solar system.
What do we have today
One of the most serious problems with this theory is the lack of records of the early history of the solar system.
However, astronomers have found two ways to get around this problem. The first is simple observation. With powerful telescopes such as the Atacama Large Millimeter / submillimeter Array (ALMA), astronomers can observe protoplanetary disks around young planets. We have numerous examples of stars around which planets are born.
The second way is modeling. To test their observations and hypotheses, astronomers create computer models. In this case, testing is carried out several times under different conditions. If all experiments show that the model works, then it is probably true.