The Atmosphere Earth Science Grade 8

The Air That We Breathe Gases: –Nitrogen = 71% –Oxygen = 21% –Trace gases: Hydrogen, helium, CO 2, CO, O 3, –Water vapor-changes from 0% to 4 % depending on the weather Liquids: Rain Solids: Snow, Sleet, Hail, dust

Water, water,everywhere The only compound found as a solid, liquid, and a gas in the atmosphere is

The Layers of the Atmosphere Thermosphere Mesosphere Stratosphere Troposphere

The layers are not very thick when viewed from outer space

The layers are cause by temperature differences

Troposphere Lowest layer of the atmosphere/ closest to the planet Where we live and breathe Where most of the gases are located Where the weather takes place

Stratosphere Where the planes fly to avoid the weather Home of the ozone layer

OZONE LAYER Layer of protection located within the stratosphere The ozone molecules collect the UV Rays coming from the SUN. Without it the temperature on the planet would be exceptionally hot…maybe too hot for life to flourish.

Mesosphere Coldest layer (That’s it, it’s very boring)

Thermosphere First layer of protection from the Sun Absorbs some of the sun’s UV rays Blends into space Where the satellites fly Where the ionosphere is located

Ionosphere A layer of charged particles (ions) floating around the atmosphere. When you send radio waves into the atmosphere, they hit the ions and bounce back to the earth. That is how you receive radio and television signals.

Radio Waves

Without the Atmosphere The energy from the Sun would heat the planet so much that we would not be able to live here. The meteors coming from space would not burn up and the Earth’s surface would look like the moon. We would not have any types of plants, which would mean that there would not be any oxygen on the planet.

Mercury has a very thin atmosphere The Moon does not have an atmosphere

When did the Atmosphere appear? The Earth did not always have an atmosphere. Erupting volcanoes early in the Earth’s history caused gases to be released and eventually collected into the atmosphere as we know it.

Without the atmosphere The energy from the Sun would heat the planet so much that we would not be able to live there. The meteors coming from space would not burn up and the face of the planet would look very different. We would not have any types of plants, which would mean that there would not e any oxygen on the planet.

Shooting Stars Meteors from space sometime enter our atmosphere. If they do, most of the material will burn up as they rocket towards Earth. This is due to the friction of the rock rubbing against the gases in the atmosphere. If they do make it completely through the atmosphere, they land as meteorites on the land or in the oceans creating craters.

Shooting stars

Meteors that do get through leave craters on the planet Barringer Crater in Arizona Inside view of Barringer Crater

Crater on USA Soil

Air Pressure Air does have mass. The air pushes down on us every second of our lives, so we don’t feel the pressure. The more atmosphere above you, the more pressure you feel. The people who live at sea-level (0ft) have the most pressure. The people who live on top of the mountain have the least amount of pressure.

Air Pressure at different heights above sea level