What is the atmosphere Definition The envelope of gases surrounding planet Earth Why do we need the atmosphere The atmosphere provides protection for the planet from objects in space and contains gasses that help sustain life ID: 605795
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Formation Of the AtmosphereSlide2
What is the atmosphere?
Definition: The envelope of gases surrounding planet Earth.Slide3
Why do we need the atmosphere?
The atmosphere provides protection for the planet from objects in space and contains gasses that help sustain life.
The atmosphere helps regulate the surface temperature, moisture, and oxygen for all living things.Slide4
How do scientists study the atmosphere?
Cameras and instruments on space satellites send back data about the structure and composition of the present atmosphere.
These studies and the studying of rocks and fossils provide clues to how the atmosphere was like in the past.Slide5
Past Atmospheres
It is thought that four billion years ago, the atmosphere contained only methane and ammonia with a little bit of water.
Methane is made up of carbon and oxygen atoms.
Ammonia is made up of nitrogen and hydrogen atoms.
Both gases are poisonous and deadly.
What do you think could have caused this deadly atmosphere?Slide6Slide7
How the atmosphere has changed over time
3.8 billion years ago, that deadly atmosphere began to change.
The change was caused by chemical reactions between the sunlight and the methane, ammonia, and water in the air.
Because of this, new materials formed:
Nitrogen
Hydrogen
Carbon dioxide.Slide8
How the atmosphere has changed over time
Hydrogen is a lightweight gas, so it escaped Earth’s gravitational pull into space.
Nitrogen was left in a huge abundance along with Carbon Dioxide and water vapor.
It was further up in the atmosphere that the sunlight began to break down water vapor in the hydrogen and oxygen gasesSlide9
The Ozone Layer
Some of those oxygen molecules combined to form a gas known as Ozone.
Eventually a layer of the gas formed about 30 kilometers above the Earth’s surface.
The ozone layer absorbs most of the harmful UV radiation from the Sun.
Without it, very few organisms would survive.Slide10
The Ozone Layer
Before the Ozone layer formed, the only organisms to survive were microbes that where lived deep below the ocean surface.Slide11
How the Ozone changed the Earth
After the formation of the Ozone, microorganisms called blue-green bacteria began to appear at the ocean surface.
These bacteria used the energy from the sunlight to combine carbon dioxide from the air and water to produce food.
The byproduct made from this food-making process made oxygen that animals would later breathe.Slide12
Green plants began to grow on the land, taking in Carbon Dioxide and releasing oxygen.
The level of oxygen on Earth began to increase dramatically.
Around 600 million years ago, the amounts of oxygen and carbon dioxide in the atmosphere began to level off.
Since then, the levels have remained fairly constant.Slide13
Present Atmosphere
In the current atmosphere, there is a mixture of the following gases:
Nitrogen
Oxygen
Carbon Dioxide
Water vapor
Solid
PsarticleSlide14
Nitrogen
Nitrogen makes up 78% of gases in the atmosphere, it’s the most abundant.
Living things need nitrogen to make proteins, which are complex compounds.
These compounds are needed for growth and repair of body parts like muscles, skin, and internal organs.
Nitrogen is returned to the atmosphere plants and animals die and decay into soil, and nitrogen is the by product of bacteria that cause decay to happen.Slide15
Oxygen
Approximately 21% of Earth’s atmosphere is made up of oxygen.
Oxygen is used directly from the atmosphere by plants and animals and is important in their respiration.
During respiration, oxygen combines with the food organisms eat and releases energy.Slide16
The last 1%
The last 1% of the atmosphere is made up of a combination of carbon dioxide, water vapor, argon, and trace gases.
Carbon dioxide is important in plant respiration, where it is removed from the atmosphere during the plant’s food-making process.Slide17
Water vapor in the atmosphere play the important role in Earth’s weather.
Clouds, fog, and dew are weather conditions formed from water vapor in the atmosphere.
Water vapor also absorbs heat, warming the atmosphere.
Depending on where you are on Earth, the amount of water vapor in the atmosphere changes.Slide18
Too much carbon dioxide a problem?
Scientists believe that there is an equal amount of carbon dioxide and oxygen in the atmosphere.
However, with the burning of fossil fuels (coal and oil) is adding more carbon dioxide.
Increasing carbon dioxide levels can become dangerous to life on Earth.
More carbon dioxide can trap the Sun’s heat, raising the surface temperature on Earth.