2.1 The Solar System Big Idea: The position of Earth in the solar system, rotation, and revolution affects weather and Human activities. In this chapter you will learn about earths, location in the universe, and the interactions of earth’s land, water, air and life.

Section 1 Discussion Questions What is the Earth’s position in the solar system? How do rotation and revolution affect the Earth? How does are position in the solar system effect earth? How does the rotation of the earth effect our everyday lives?

Section 1 The Solar System Space and earth = universe Stars=galaxies= The Milky Way (us) A. Planets 1. Solar System - sun & group of bodies that revolve around it (planets, dwarf planets, small solar system bodies like asteroids and comets.) 2. 8 planets- Pluto considered dwarf planet in 2006 (International Astronomical Union) has a small rocky core. 3. Earth and other planets are shaped like a oblate spheroid -flattened at poles and bulging at equator 4. Moons are natural satellites that orbit planets This photo is of the Eagle Nebula in 1995 from the Hubble telescope ( 1st telescope placed in orbit around earth) and it shows where new stars are forming. The pillars are gas and dust that when condensed and ignited create stars. The light from these stars takes travels 186,282 miles per second, but still takes ten billion years to reach the light of the telescope. Space and the Universe When you look at the night sky you see stars, which are part of the universe. Universes is made up of all existing things including space and earth. Universe is 10-20 billion years old. Space is filled with large objects called stars. When stars are group together in large clusters it is called galaxies. The Milky Way is the galaxy in which we live and all the planets we learn about in school are in. The planets Solar system is the sun a group of bodies around it. Because of the sun these objects are attracted to it through gravity. Planets do not generated their own light but instead it is reflected from the sun. Pluto and UB313 ( largest dwarf Xena) are considered dwarf planets. planets are flat at the top and bulging in the center around their equators. Moons are natural satellites that orbit the planets. we have one moon but many man made satellites. Mercury and Venus have no moons and Saturn has eighteen moons. The Tunguska Event Asteroids have direct impact on the planet. They are natural satellites and when they impact the earth they cast off fragments of dust and some become meteors. If a meteor exploded just beyond the earths surface it can cause wide spread damage. Scientist believe such an event occurred in Siberia Russia June 30, 1908. It destroyed thousands of miles of subarctic forest with a force 1,000 times greater than the force we released on Hiroshima Japan during WWII. Effects recorded after include disturbances in the earths magnetic field and genetic mutations in certain plant and animal species. Videos Solar system picture goes over all the planets ( national geographic) Asteroid hitting the earth picture is an animated movie of the earth being hit. Asteroid photo is the WWII bombing of Japan and comparable to an asteriod ( study asteriod impact to understand such things) Burnt tree photo of Tunguska Russia measures and asteroid impact

B. The Sun, Earth and Moon 1. Diameter of Earth is 8,000 miles * 3rd from sun and 5th largest * Has an elliptical (oval Shaped Orbit ) 2. Diameter of Sun is 865,000 miles (Bigger than Earth) 3. Moon orbits Earth every 29.5 days and is ¼ the size of earth. 4. All exert gravitational forces on each other which affect physical processes on Earth like tides. The sun is an average star in age and in size. It is responsible for heating up the solar system. Moon has no air water or life and has many craters because of meteor impact. These to forces exert gravitational pull on the earth which influence the natural processes on earth. A good example of this is ocean tides.

Tides geography Asteriod photo is the WWII bombing of Japan and comparable to an asteriod Picture of waves connects to national geographic and is used to explain waves and how they work. when the sun and the moon are combined tides are higher than normal called spring tides occur twice a month during the full or new moon. When the sun and the moon are separated by forty five degrees it is a neap tide and is lower than a high tide. This happens during quarter moons. The picture with ships is an example of high tide in the Bay of Fundy. These are some of the highest tides on earth located off the southeastern shore of the Canadian Providence of Nova Scotia. They can reach heights of more than fifty feet at high tide. Because the bay in narrow and works as a funnel neck the water has no place to go and can’t escape. As a result of this the water piles up. Another spectacular phenomena of this is the tidal bore ( tidal bore picture is a video). As the incoming water rushes in the water pushes up stream and causes rivers to rise and reverse their flow.

Earth’s Rotation, Revolution and Tilt A. Solar Energy-energy from sun in form of heat and light. It impacts life in many ways. B. Rotation 1. Earth spins on axis- allows equal heat and cooling 2. One complete spin is called rotation (24 hours) 3. Rotates from west to east - sun rises in the east and sets in the west Most of earths energy comes from the sun known as solar energy. How much solar energy a place receives depends on the earths tilt in that region. This affects the clothes we wear, crops we grow, and even sports we play. Imagine the earth is spinning on a rode which one spin on the axis = one 24 hr day Remember the international date line is where a new day starts. Because the earth is spinning all parts of the earth are able to receive solar energy even though the amounts differ.

C. Revolution- Earths elliptical orbit 1 C. Revolution- Earths elliptical orbit 1. Earth makes one trip around the sun in 365 ¼ days in an ellipse. 2. Feb. 29th is added every 4 years to make that year 366 (leap year) Not only do we rotate on an axis, but we also revolve around the sun. This means that we circle the sun using an elliptical orbit. This takes 365 ¼ days which equals our year. To make things easy our year is 365 days, except when the extra fourth of a day add up to equal a full day then we have a leap year February 28th.

1. Tilted at 23 ½ degrees as it orbits D. Tilt 1. Tilted at 23 ½ degrees as it orbits 2. The tilt affects the amount of solar energy hitting the earth Reading Check: How do rotation, revolution and tilt affect the amount of solar energy received at different locations on the Earth? If earth was not tilted on it’s axis everywhere in the world would experience 12 hrs of day light and 12 hrs of night. Because it is tilted on an axis this is not the case. As the earth revolves around the sun the axis stays tilted in the same direction ( refer to the picture). The axis is fixed in relation to the north star.