How did oceans form from the early atmosphere?

Oceans formed from the early atmosphere through a process called outgassing, followed by condensation and precipitation.

In the early stages of Earth's formation, the planet was extremely hot and volatile. The heat was primarily due to the decay of radioactive elements and residual heat from the planet's formation. This intense heat caused the rocks to melt, forming a molten surface. As the Earth cooled, gases trapped within these rocks were released into the atmosphere, a process known as outgassing. The primary gases released were water vapour, carbon dioxide, and nitrogen.

Over time, as the Earth continued to cool, the water vapour in the atmosphere began to condense. This is similar to how water droplets form on the outside of a cold glass on a hot day. As the water vapour condensed, it formed clouds. When the concentration of water in these clouds became too great, it fell as rain in a process known as precipitation.

This rainwater collected in the lowest parts of the Earth's surface, forming the first oceans. Over millions of years, these bodies of water grew in size, eventually forming the vast oceans we see today. It's important to note that this process was not a one-time event, but rather a continuous cycle of evaporation, condensation, and precipitation that still occurs today.

The formation of oceans was a crucial step in the development of life on Earth. The oceans acted as a reservoir for carbon dioxide, helping to regulate the Earth's climate. They also provided the necessary conditions for the first life forms to develop, marking the beginning of the evolution of life on our planet.