- From what sources did water arrive in Earth’s atmosphere?

- What are the two main reasons that an oxygen-rich atmosphere is important for life on Earth?

Question

- From what sources did water arrive in Earth’s atmosphere?

- What are the two main reasons that an oxygen-rich atmosphere is important for life on Earth?

thomaster · Answer

From space... meteorites can contain ice.

Because a lot of organisms cannot live without oxygen
Second, oxygen makes up the ozone layer. without that layer, you won't need a grill to bbq anymore. The downside: many people would get skin cancer due to UVb radiation.

agreene · Answer

another source of water was outgassing of rocks formed during the earth's creation, which were probably high in water from the solar nebula. Although, the current understanding of the Hadean would lead us to think this would be a very small amount.

anonymous · Answer

water is formed by the composition of hydrogen and oxygen from the space of earth's atmosphere.             Oxygen is needed for all the living things which use oxygen and  it helps many oxide reactions to occur.

tanya123 · Answer

thank you all @thomaster , @agreene and @Blacksmith97 for the great explaining !!!!