The Earth’s Atmosphere

Learning Goals By the end of the lesson, we will be able to… …analyze documents to locate facts and details …make inferences about at least 3 major ways the Earth’s atmosphere supports life …clearly explain in writing with supporting details the reasons why Earth is just right for life

The Goldilocks Theory Just as Goldilocks found the porridge that was just right, the Earth seems to be just right for living creatures. Mystery: Why is the Earth’s atmosphere “just right” for supporting life ?

Our Hypothesis We think that the Earth’s atmosphere is “just right” for supporting life because it holds anough oxygen for us on the planet.

Clue #1 Source: Gases that make up Earth’s Atmosphere 78 % 21%

Clue #2 From Biology for Kids.com: “All animals take oxygen into their bodies. The oxygen is then passed around the animal’s body through circulation. The oxygen helps all of their cells to work correctly.” “Nitrogen is absorbed by both plants and animals, and it helps them to live and grow.” Lungs

Clue #3 PlanetGases Available in Planet’s Atmosphere Jupiter Ammonia, Methane, Helium, Hydrogen, Sulfur Neptune Methane Mars Carbon Dioxide Earth Nitrogen and Oxygen

Clue #4 From the Australian News Today: “Last night, a meteor streaked across the sky. People in town saw a bright light for a few seconds in the sky. A local scientist explained that the meteor was a rock from outer space moving towards Earth. The meteor was burned up in the Earth’s atmosphere before it could reach the Earth’s surface. “ Click on picture to play movie clip

Clue #5 From Geography4Kids.com: “The Earth’s atmosphere is like a cozy blanket because it traps in heat from the sun and warms the Earth. Scientists say the Earth would be an average of 57 degrees colder without the atmosphere to trap heat from the sun.”

Clue #6 The ozone layer is a part of the atmosphere that acts like a shield high up in the sky. It blocks some of the sun's harmful ultraviolet (UV) rays. Too many UV rays can cause bad health effects like skin cancer, eye damage.

Clue #7 NASA Scientists Report: The atmosphere of Venus is very hot and thick. Plants and animals would not survive a visit to the surface of the planet – the air is poisonous and the temperature is extremely high. The surface and atmosphere of Venus is one of the hottest places in the solar system! Source:

Clue #8 NASA Scientists report: The atmosphere of the planet Neptune is extremely cold. There are icy clouds and enormous storms. Animal and plant life would not survive the extreme cold. Tremendous winds whip around the planet. Winds were measured to be about 1,500 miles per hour. To think about how fast that wind is, the strongest winds in Hurricane Katrina were only 140 miles per hour.

Clue #9 Venus is closer to the sun than Earth, and the atmosphere is too hot for liquid water on its surface. In fact, it is so hot that, like a sauna, all the water has been evaporated into the atmosphere. Mars is farther from the sun than Earth, and the atmosphere is too cold for flowing water on its surface. The only water available is frozen. All life needs liquid water to survive.

Solving the Mystery Okay, Detectives! You have gathered all of your clues about how the Earth’s atmosphere is “just right” for supporting life. Revisit your initial hypothesis and use your information from the clues in a new, stronger, and more specific hypothesis. Type your hypothesis in the next slide.

Mystery Solved! Our New Hypothesis:The Earth is perfect because the atmosphere is just right and it is not to cold and not to hot.The level of oxygen is just right.Some other planets don’t have oxygen,like Mars.Mars has carbon dioxide.

Tip: Done Early? Review your work – could you add more details and evidence to make your hypothesis stronger? Don’t forget to save! Press the Save button in the upper left corner of the screen.