What do we currently believe was the main source of the Earth's oceans and atmosphere?

Question

Quizplus · Accepted Answer

The current scientific consensus is that the main source of the Earth's oceans and atmosphere was outgassing by volcanoes. As early Earth cooled, gases trapped within the mantle were released through volcanic activity, forming the primordial atmosphere. Water vapor was also released through volcanic outgassing and combined with other elements to form the oceans. While impacts by icy planetesimals and material from the solar nebula may have contributed to the Earth's water supply, they are not considered the main source. Melting and vaporization of polar glaciers is also an unlikely source as glaciers only cover a small portion of Earth's surface.

What Do We Currently Believe Was the Main Source of the Earth's