The formation of our Solar System involved a series of complex processes and events. The Ryugu asteroid, which was explored in great detail by the Japanese space mission Hayabusa2, provides essential clues to unlock the secrets of what happened before, during, and after the formation of the Solar System. Here's a summary:

Before Solar System Formation:

1. Nebula Formation: The Solar System began with a giant interstellar molecular cloud known as a nebula. This cloud was composed of gas, dust, and tiny solid particles.

2. Gravitational Collapse: Within the nebula, a region of slightly higher density started to collapse under its gravitational force. This region marked the beginning of the protoplanetary disk.

During Solar System Formation:

1. Disk Accretion: As the protoplanetary disk continued to collapse, it began to rotate more rapidly. This caused material to be drawn towards its central region, forming a dense and hot core that would eventually become the Sun.

2. Planetesimal Formation: Solid particles in the protoplanetary disk started to collide and agglomerate into tiny objects known as planetesimals. These were the building blocks of larger planetary bodies.

3. Protoplanet Formation: Over time, through further collisions and gravitational interactions, planetesimals grew in size, forming protoplanets, including the early versions of Earth, Mars, and Jupiter.

4. Gravitational Clearing: Gravitational forces from protoplanets cleared out debris and smaller objects in their orbits, shaping the early Solar System.

After Solar System Formation:

1. Orbital Adjustments: The orbits of planets were not fixed and underwent significant changes during the early stages. Collisions and gravitational interactions modified the shapes of planetary orbits and influenced the trajectories of celestial bodies.

2. Planetary Evolution: Planets developed different characteristics based on their size, composition, and distance from the Sun. Gas giants like Jupiter acquired large atmospheres, while rocky planets like Mars and Venus underwent geological processes.

3. Asteroid Belts and Kuiper Belt Formation: Leftover debris that didn't form into planets accumulated in specific regions of the Solar System, giving rise to the asteroid belt between Mars and Jupiter and the Kuiper Belt beyond Neptune.

4. Late Heavy Bombardment: Approximately 600 to 800 million years after the formation of the Solar System, the inner Solar System experienced a period of intense asteroid and comet bombardment, which shaped and scarred many planetary surfaces.

The exploration of Ryugu provided insights into the early conditions and processes that took place during the formation of the Solar System. By analyzing samples collected from Ryugu, scientists have gained valuable information about the composition, mineralogy, and chronology of the Solar System's early stages. This has allowed researchers to better understand how the planets and other celestial bodies came into being and evolved over billions of years.