Question

According to scientific data and analysis, what led to the formation of the early atmosphere of Earth?

Answer 1

When Earth formed 4.6 billion years ago from a hot mix of gases and solids, it had almost no atmosphere. The surface was molten. As Earth cooled, an atmosphere formed mainly from gases spewed from volcanoes. It included hydrogen sulfide, methane, and ten to 200 times as much carbon dioxide as today's atmosphere. So it would be Outgassing. Hope that helped :)