Date Vocabulary moon: a planetary body (usually composed of solid elements) that orbits another planetary body. Announcements:

Our Moon

PA Standards S8.A.1.3.1 Use ratio to describe change (e.g., percents, parts per million, grams per cubic centimeter, mechanical advantage). S8.A.3.2.1 Describe how scientists use models to explore relationships in natural systems (e.g., an ecosystem, river system, the solar system). S8.C.3.1.1 Describe forces acting on objects (e.g., friction, gravity, balanced versus unbalanced). S8.D.3.1.2 Describe the role of gravity as the force that governs the movement of the solar system and universe.

Moon Facts The moon is between 225,622 and 252,088 mi from earth. The earth has a diameter of 7,926 mi. So you could fit 29 earths between the earth and the moon. The moon does not produce it’s own light. The light you see coming from the moon is light reflecting off the moon from the sun!

Cultural Importance The lunar cycle has been used by most cultures as a way to count the passage of time. The word “month” refers to the length of a lunar or MOON cycle. “Monday” is the 1st day of a week. “Lunatic” is someone who is affected negatively by the moon showing that it’s believed to have some power over people.

“Super Moon” On March 19th, 2011 the full moon appeared larger than normal in the night sky. This is because of the Moon’s elliptical orbit bringing the moon closer to Earth. This is the closest the moon has been to earth since 1983. The closeness did cause a rise in tides of a few cm. Contrary to rumors in the media, supermoons DO NOT cause natural disasters. Don’t believe everything you hear on TV or read on the internet!

Lunar Cycle 28 days “Period” Waning = left side (but not half or whole) is illuminated. Waxing = right side (but not half or whole) is illuminated. Gibbous = between half and full. Crescent between half and new.

The Moon Illusion Ever notice that when the moon is high in the sky it looks smaller than when it is lower, near the horizon? This is an optical illusion! Objects we are used to seeing in the sky appear smaller as they move toward the horizon-away from us. This gives our brain the idea that objects on the horizon appear smaller because they are farther away. When the moon is low and on the horizon, our brain tries to apply the same idea when in actuality it is 1.5% smaller than it is when you see it high in the sky!

Formation of Our Moon

Composition

Geography The moon does not have actual oceans of water. The moon is covered by impact craters from billions of years of meteorite and asteroid impacts. The Earth is much bigger than the moon and has had just as many impacts if not more than the moon. So why don’t we see all of the impact craters on earth (there are 2 reasons).

Moon’s Effect on Earth Impact cause the 23.5° tilt of the Earth. Moon’s orbit/gravity has stabilized that tilt. Moon’s gravity causes tides. The core of the impactor that gave us our moon is what has given us a great abundance of metals in our crust as compared to other terrestrial planets.

Lunar Eclipse

Missions to the Moon The Soviet Union was the First country to (crash) land a craft on the moon. The US Apollo missions were manned missions where astronauts walked on the moon and collected samples. The USSR Luna missions were rover missions that collected data and took pictures of the surface of the moon.

Apollo 11

Other Moon Landings There have been 75 unmanned missions to the moon between the US and USSR of which 32 were successful. The United States has successfully landed 6 manned crews on the moon. 12 different men have walked on the surface of the moon. It should be noted that the US and USSR were NOT working together!

Was it a Hoax? NO There are retroreflectors that were left there by Apollo 11, 14, and 15 that anyone with a powerful enough LASER can bounce a beam off of. By the way…the footprints are still up there. Why?

A Base on the Moon? The diagram is just one concept of what a Lunar Base could look like. What would be the challenges of living in a Lunar Base? What would be the advantage of having a base on the Moon?

Our Moon compared to other Moons

Recap 1. Why does the moon appear larger when it is on the horizon? 2. What 3 effects does the moon have on the Earth? 3. How many humans have walked on the moon and where were they from?