Likely white or grayish atmosphere: The first atmosphere developed first but was not directly involved in the development of life. The first atmosphere formed shortly after Earth’s formation around 4.5 billion years ago. This initial atmosphere was primarily composed of hydrogen and helium, the lightest and most abundant elements in the universe, which were captured from the solar nebula.

This first atmosphere was very thin and likely dissipated into space due to Earth’s weak gravitational pull at the time and the intense solar winds from the young Sun.