The statement that water on Earth is older than our whole solar system might be misleading or misconstrued. Let's clarify some important points:
Formation of the Solar System: The Solar System formed approximately 4.6 billion years ago from a giant molecular cloud composed mostly of hydrogen and helium. This cloud eventually collapsed under its own gravity, forming a rotating disk known as the protoplanetary disk.
Water in the Universe: Water is a relatively common molecule in the universe. It consists of two hydrogen atoms and one oxygen atom (H2O) and can be found in various forms, such as gas, solid ice, or liquid. Water molecules have been detected in interstellar clouds, protoplanetary disks, and even in other star systems.
Origin of Earth's Water: The exact origin of water on Earth is still a topic of scientific investigation and debate. There are multiple theories, but the most widely accepted one suggests that Earth's water came from a combination of two main sources:
a. Inherent Water: Some water might have been present on Earth during its formation, trapped within the materials that accreted to form the planet. This water is commonly referred to as "inherent" or "primordial" water.
b. Late Heavy Bombardment: Another significant contribution of water to Earth came from comets, asteroids, and other small bodies during a period called the Late Heavy Bombardment. This event occurred around 4.1 to 3.8 billion years ago, when the early Solar System was still dynamically active, resulting in a heavy influx of water-rich bodies colliding with Earth.
It's important to note that while water molecules have been found in interstellar space and in other star systems, the specific water molecules on Earth have likely undergone various processes and interactions throughout our planet's history.
So, while it's true that water is an ancient and widespread molecule in the universe, the water on Earth, in its current form, is a product of complex processes that occurred after the formation of our Solar System.