EVERYDAY SCIENCE

Detailed explanation-1: -Earth’s original atmosphere was rich in methane, ammonia, water vapour, and the noble gas neon, but it lacked free oxygen.

Detailed explanation-2: -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.

Detailed explanation-3: -A cataclysmic meteorite bombardment kept much of Earth’s surface in the molten state; the incoming impactors may have brought additional water, methane, ammonia, hydrogen sulfide, and other gases that supplemented the atmosphere.

Detailed explanation-4: -The early atmosphere was hostile. We think the Earth’s early atmosphere was made up of mostly carbon dioxide, lots of water vapour and very small amounts of methane and ammonia. These gases made it extremely hostile. There was no oxygen, making it similar to the atmosphere of Mars and Venus today.

Detailed explanation-5: -The proportion of ammonia decreased as it reacted with the newly formed oxygen in the atmosphere to form nitrogen and water vapour. The proportion of methane decreased as it reacted with the newly formed oxygen to form carbon dioxide and water.