1. Explaining Earth’s Position & Motion in the Universe
Earth in the Universe
Explaining Earth’s Position & Motion in the Universe

2. What is a Universe?
A celestial creation made up of many galaxies—approximately 10 billion years old
A galaxy is made up of stars & planets (ex. The Milky Way )
Milky Way is the galaxy of which the planet Earth is a part
There are many different galaxies that seem to have common elements, forces, forms of energy, & physical principles

3. Organization of Universe
Universe>solar system>planets (Mercury, Venus, Earth, Mars, Jupiter, Saturn Uranus, Neptune, & Pluto*)
Planets orbit around the Sun
Moons orbit around planets (ex. One moon orbits around Earth)
Earth is the only planet currently known to support life while maintaining a delicate balance with the sun

4. Studying the Universe
Technology makes it possible for us to study the universe: radio & x-ray telescopes; space probes
All of what we study about the universe is based on inferences from observations taken with technology tools

5. Planet Earth I Approximately 4.6 billion years old
Spherical in shape due to the mutual gravitational attraction pulling its materials toward a common center (center of the Earth & center of the moon) barycenter
Mostly rock
¾ of surface is covered by water
Wrapped in a thin layer of air

6. Planet Earth 2
Water bulges on both sides of planet due to gravitational pull of sun & moon—creates tidal waves (also see tidal impact)
Gravitational pull of Earth’s mass maintains the atmosphere
Earth is a safe enough distance from the sun—provides enough radiation to sustain living things & not boil all the water in the oceans

7. Planet Earth 3
Water on Earth is in form of liquid, solid & gas (rarity)
Earth’s motion & positions in relation to the sun & moon create a huge impact
Seasonal variations of climate are caused when 1/2 of Earth receives direct sunlight while the other ½ does not—this happens because Earth’s tilted on its axis during its 1-yr revolution)
Revolution: moving around a mass or body

8. Planet Earth 4
The rotation on it’s axis in 24hrs gives us night and day
Rotation: spinning on its axis
Earth’s motion & moon orbiting around the Earth (once per 28 days) gives us the phases of the moon; depends on the changing angles whether we see waxing or waning phases

9. Summarize Directions: Answer the EQ from lessons 1 and 2.
Scan back through the slides looking for 3 bold print words. Write a sentence using the correct meaning of each term. Complete this inside your composition book.