Science Project
Storyboard Text
- The Earliest Atmosphere - 4.6 billion years ago
- The Archean Eon - 4 to 2.6 billion years ago
- Oxygen at Last - 2.6 billion to 400 million years ago)
- When Earth formed 4.6 billion years ago, it had almost no atmosphere. As Earth cooled, an atmosphere formed from gases released from volcanoes. After about half a billion years, Earth’s surface cooled and solidified enough for water to collect on Earth.
- Oxygen Boom! - between 700 to 550 million years ago
- 2.7 billion years ago, bluish-green microscopic organisms called cyanobacteria created free (gaseous) oxygen from carbon dioxide, water, and sunlight—the process called photosynthesis.
- The Age of Oxygen - 400 million to 290 million years ago
- Life and Earth's atmosphere evolved together. About two billion years ago, the methane haze cleared and the sky turned blue.
- Modern Atmospheres - 290 million years ago to now
- oxygen levels in the oceans and atmosphere increasedAt the beginning of this (Devonian) Period, the Earth was warm. More plants and soil reduced the amount of carbon dioxide in the atmosphere-the Earth grew cooler.
- As plants became established on land, life once again had a major effect on Earth’s atmosphere during the Carboniferous Period.
- During most of the past 290 million years, Earth was much warmer than it is now. In these warm climates, many types of plants and animals lived in the polar regions.
Over 30 Million Storyboards Created
No Downloads, No Credit Card, and No Login Needed to Try!
