The Formation of the Solar System from Galactic Collisions - The following is an article that discusses collisions between solar systems that trigger the formation of the solar system which has been summarized from reliable sources.
Astronomers already know that the smaller Sagittarius galaxy repeatedly crashes into the disk of the Milky Way as it orbits around the galactic core. This is caused by the force of gravity. In previous research, the Sagittarius galaxy, which is a dwarf galaxy, has an influence on the motion of stars in the Milky Way. Even astronomers estimate that the Milky Way's more massive 10,000 times spiral structure is the result of 3 collisions with the Sagittarius galaxy in the last 6 billion years.
Recent research from the Gaia data has shown that the dwarf galaxy Sagittarius has a greater influence on the Milky Way than previously thought. The ripples caused by the collisions may have triggered large-scale star formation. And presumably, this incident coincided with the formation of the Sun 4.7 billion years ago.
From existing models, it is known that the Sagittarius galaxy fell into the Milky Way 3 times. The first was around 5-6 billion years ago, then about 2 billion years ago, and the last one was around 1 billion years ago. From Gaia's observational data, when Sagittarius hit the Milky Way, there was an increase in star formation in the range of 5.7 billion years ago, 1.9 billion years ago, and 1 billion years ago. At that time, the Sagittarius galaxy was crossing the Milky Way's disc.
Ripples in Water
In this study, astronomers analyzed the luminosity, distance and color of stars in a circle 6500 light-years in diameter around the Sun for comparison with existing stellar evolution models.
Initially, the Milky Way was fairly calm and stable, after its early star formation. When equilibrium is formed, star formation occurs steadily. However, this stability is then shaken when Sagittarius falls or hits the Milky Way. As a result, the gas and dust that had calmed down became disturbed and overflowed producing ripples like water.
In some areas of the Milky Way, these ripples produce huge concentrations of gas and dust but empty other areas. The material that is in an area of high density is then triggered to produce star formation.
So, the Sagittarius collision not only affected the motion of the stars in the Milky Way but also helped shape the structure of the Milky Way.
Birth of the Sun
It seems that the birth of the Sun and the planets around it were actually triggered by the collision of the Sagittarius galaxy. It is not certain whether the gas cloud that formed the sun collapsed due to the collision of the Sagittarius galaxy. However, the collision and the formation of the Sun happened at the same time so it is possible that it could.
In each collision, the Sagittarius Galaxy experiences loss as gas and dust. As a result, the dwarf galaxy is getting smaller. Allegedly, this dwarf galaxy has just passed through the Milky Way in a few hundred million years and is still quite close. Not only that, it was also found that there was an explosion of star formation at that time.