 Earth is the 3 rd terrestrial (made of rock) planet from the Sun.

 Over the centuries, theories about the Earth, and the things that happen on Earth, have changed through many observations.

 For centuries, educated people though this world was flat like a map.

 About 1700 years ago, Aristotle (Greek smart-guy) said the Earth was round because it made a round shadow on the moon during an eclipse. Most did not take him seriously.

 Sailors thought Earth was round, because the tops of objects, moving inland, were seen first.  The “Earth is round” theory was not proven until 1492.

 Other proof of Earth’s shape was the way stars moved across the sky over time—in a high-to-low curve.

 The Earth spins (rotates) on an Axis (imaginary line) at 1070 mph, which takes 24 hours for it to turn once.

 Only one side of Earth can face the light at one time, so this rotation causes night and day, and makes it look like the sun moves across the sky.

 Throughout history, many cultures had their own theories for the Day and Night changes.

 Things like compasses, animal migrations, and the Aurora Borealis were theorized to be the result of Earth’s “magic.”  These are actually caused by Earth’s invisible Magnetic Field.

 Because of Earth’s iron core, the planet acts like a giant magnet, and has a North and a South Magnetic Pole.

 The surrounding magnetic field of Earth point compasses North, and move energized particles from the Sun into colored light at the Poles. (Aurora Borealis)

 Earth’s magnetic field is also used by migrating animals to find North/South.

 Earth’s magnetic poles slowly move around over time, and some people theorize that a drastic magnetic pole change could happen, causing destructive climate changes, and make India the new North Pole !

 Many people think that the Earth’s orbit around the sun is a perfect circle—its not!  The orbit is an Ellipse—an egg-shape. The Sun also sits a little off-center of Earth’s orbit.

 The Earth does not rotate perfectly straight on its Axis either—it is tilted.

 These imperfections in our revolution (orbit) and rotation (spin) create our seasons.

 In the Spring/Summer for Northern Earth, the planet tilts towards the Sun, but is further away from it during its revolution.  This focuses the Sun’s energy over a wide area in the Northern Area, creating longer days of sunlight.

 In the Fall/Winter for Northern Earth, the planet tilts away the Sun, but is closer to it during its revolution.  This focuses the Sun’s energy in a smaller area in Earth’s Southern Hemisphere, giving the Northern part shorter days of sunlight.

 A Solstice is the day when the Sun, due to Earth’s elliptical orbit-shape, is the farthest North, or farthest South of Earth’s Equator.

 The Summer Solstice is the longest “day” (June 21/22, Northern Hemisphere) because it’s the time when the largest area of sunlight shines on Earth’s Northern Hemisphere.

 The Winter Solstice is the longest “night” (December 21/22, North) because it is the time in Earth’s orbit when the smallest area of sunlight shines on the Northern Hemisphere.

 The Equinoxes is the 2 times during Earth’s Revolution (aka orbit) when the sun shines directly above the Equator. (Equi = equal).  All over the world (for that day) Day and Nighttime is equal.

 During an Equinox, Neither the Northern Hemisphere, or the Southern Hemisphere tilts towards or away from the Sun at all.

 For any seasonal change that happens on the North Hemisphere, the exact opposite happens in the South, because it is the exact opposite side of Earth.

 Just like the Earth orbits the Sun, our moon orbits the Earth.  The moon spins on its own axis, like Earth, but you always see the same side of the moon.

 This is because the moon’s rotation is slow—it takes over 27 days for the moon to rotate once, and it takes the same amount of time for 1 revolution around Earth.

 Ancient Greeks thought the moon was the Goddess Artemis (sister of Apollo, the Sun god) riding her silver chariot across the sky.

 Later, during the Medieval period and the Renaissance, people thought the moon was a smooth glowing ball.

 Today we know that moonlight is just sunlight reflecting off the moon’s surface, and bouncing back towards earth.

 There were 3 theories about how the moon was created.

 1. The moon was a large asteroid captured by Earth’s gravity.

 2. The moon was created at the same time as the Earth out of a cloud of dust and gases in the early solar system.

 3. The other 2 theories were proven wrong, and a new theory was created after the Apollo moon mission on : The Impact Theory.

 Billions of years ago, the recently formed Earth is a ball of semi-molten rock.  An asteroid, roughly the size of Mars, crashes into Earth.

 The collision sends a splattering of lava, dust and rock into space.  The “splatter” then is captured into Earth’s gravity, and begins to orbit.

 While in orbit, the “splatter” condenses into a ball, forming the Moon.  Over the millions of years, meteors collided with the moon, forming its “seas” and craters.