Life in our solar system Unit 5 Life in our solar system

7.9A Characteristics of the Solar System Student Expectation The student is expected to analyze the characteristics of objects in our solar system that allow life to exist such as the proximity of the Sun, presence of water, and composition of the atmosphere.

Proximity to the Sun Proximity to the Sun contributes to temperature ranges experienced by a celestial body. Distances that are too close or too far from the Sun create extreme temperature conditions that are considered inhospitable to life.

Habitable Zone Earth is around 93,000,000 Miles from the Sun, which is a distance favorable to supporting life. Venus is too hot (464° C), and Mars is too cold (-65° C). Earth’s average surface temperature Is 15° C, or 60° F.

Discuss with a shoulder partner ‘How does the distance from the Sun affect the conditions necessary for life?’ Distances that are too close or too far from that Sun create extreme temperature conditions that are considered inhospitable to life.

Composition of the Atmosphere The presence and composition of an atmosphere contributes to the ability of life to exist. Atmospheric gases help regulate extreme temperature variations and ozone in the atmosphere shields living things from harmful ultraviolet radiation. The magnetosphere, formed by Earth’s magnetic field, protects life from the charged particles of the solar wind.

Earth’s Atmospheric composition by the Numbers Without greenhouse gases, such as carbon dioxide and water vapor keeping the Earth warm, Earth’s temperature would be -33° C.

Presence of Water Earth is known as the water planet with about 70% of its surface covered by water. All life on Earth depends upon the presence of water. There is geological evidence that liquid water was once present on the surface of Mars. Scientists speculate that water exists, in various states of matter, on other celestial bodies in our solar system.

Discuss with a shoulder partner ‘Earth supports life while the nearby Moon does not. Describe three reasons why The Moon cannot support life compared to the Earth.’ The three characteristics (atmosphere, gravity, and water are all possible answers).

7.9B Accommodations for Space exploration Student Expectation The student is expected to identify the accommodations, considering the characteristics of our solar system, that enabled manned space exploration.

Microgravity Astronauts must exercise regularly while in space because a microgravity environment can cause muscles and bones to  become weak and less dense. Handles, tethers and Velcro® straps are accommodations that help astronauts to move around, sleep safely and complete other tasks that normally utilize the force of gravity. Microgravity video clip

Ultraviolet Radiation The visor is coated with a thin layer of gold  that filters out the sun's harmful rays. Most of the spacecraft windows are coated with ultraviolet blockers. The EVA (extra vehicular activity), or spacewalk suit has a layer of material to block ultraviolet radiation.

Micrometeoroids Micrometeoroids are tiny meteoroids traveling fast enough to damage a spacecraft, or spacesuit.

Gravity assist maneuver (Gravitational Slingshot) Gravitational assist is a way of using the motion of a planet to accelerate a space probe on its journey towards the outer planets.