Solar System | A short recap

• 4.6 billion years ago: The Solar System is formed from a rotating cloud of gas and dust.
• 4.5 billion years ago: The Sun ignites and becomes a star.
• 4.4 billion years ago: The oldest known rocks on Earth, called the Acasta Gneiss, are formed. They contain minerals that suggest they were formed in a magma ocean, likely caused by the impact of a Mars-sized object with Earth.
• 4.1 billion years ago: The Late Heavy Bombardment occurs, which is a period of intense meteorite impacts on the inner planets.
• 3.8 billion years ago: Life on Earth begins to emerge in the form of simple single-celled organisms.
• 3.5 billion years ago: Photosynthesis evolves, which leads to the oxygenation of Earth’s atmosphere.
• 2.5 billion years ago: The Great Oxygenation Event occurs, which dramatically increases the amount of oxygen in Earth’s atmosphere.
• 1.3 billion years ago: Complex, multicellular life emerges on Earth.
• 4.5 million years ago: The protoplanetary disk that formed the Solar System begins to dissipate.
• 4.56 million years ago: The oldest known meteorites, which contain material from the early Solar System, are formed.
• 4 billion years ago: The inner planets, including Earth, are bombarded with comets and asteroids, bringing water and organic molecules to the surface.
• 2 billion years ago: The first evidence of life on other planets may have formed around this time.
• 1 billion years ago: The Moon is formed after a Mars-sized object collides with Earth.
• 600 million years ago: The earliest known animals appear on Earth.
• 200 million years ago: The supercontinent Pangaea begins to break apart, leading to the formation of the modern continents.
• 65 million years ago: A large asteroid collides with Earth, leading to the extinction of the dinosaurs and many other species.
• 4.5 million years ago to present: The Solar System continues to evolve, with the planets and other objects in the system interacting with each other in complex ways. Humans develop the technology to explore the Solar System and send spacecraft to study its objects in detail.