The MOON!!! Our Closest Celestial Neighbor
Our only natural satellite Mass: 0.012 of Earth s Diameter: New York to San Francisco Surface Gravity: 1/6 of Earth s Little to no Atmosphere
Earth-Moon Distance If the Earth was a Basketball & the Moon was a tennis ball, how far apart would they be? What s your guess?
How does it size up?
Round due to high speed impact of meteors (112,000 mph) Craters With an Earth-based telescope, over 30,000 craters are visible Up to 1,000 km wide
Lunar Geography Highlands Heavily cratered areas Lighter, whiter regions Oldest parts of the Moon (4 billion years old) Covers 83% of Lunar surface Maria mar-ee-ah, Latin for seas Comparatively smooth, flat areas Darker regions Newer parts of the Moon (3.5 billion years old) Covers 17% of Lunar surface
1. Caused by deep impacts from meteors 2. Surface cracks, liquid magma from underneath floods up 3. Magma cools Maria
Why almost no atmosphere? 1. No magnetic shielding from solar winds (no active inner core) 2. Probably didn t form with much However, moon rocks naturally secret gasses, supplying a tiny & steady amount of gas
First to the Moon The USSR was the first to send a probe that landed on the moon. Luna 2 September 13 th, 1959
Direct Observations! The Moon is the only place outside of Earth that people have ever visited! The first Moon landing Name? Apollo 11 NASA mission When? July 20, 1969 Who? 1 st : Neil Armstrong 2 nd : Buzz Aldrin 3 rd :????
NEVER FORGET! Michael Collins
Why didn t Michael Collins get to walk Two separate vehicles, the Command/Service Module (CSM) and the Lunar Module (LM). on the Moon too? Collins manned the CSM while Aldrin and Armstrong descended in the LM.
Apollo 11 Moon Landing Landed in Mare Tranquillitatis Sea of Tranquility The historic moment If you disrespect a hero
6 Manned Moon Landings
What they found (and brought back) Regolith fine powdery rock, like ash, covers the Moon. 1-20 meters thick! Lots of Rocks! Brought back 842 lbs. ( 69 72) No Water That we noticed at the time Cheese Transformers
Two main kinds of rock Basalt dark, volcanic rock full of heavy elements Maria Anorthosite brighter, reflective Full of Ca & Al oxides Highlands
How did the Moon get there? Fission Theory Capture Theory Co-creation Theory Collision-Ejection Theory
The Moon was originally part of the Earth It was pulled out, midformation, while the proto-earth was still molten CONS: Why isn t the Moon just like a Jr. Earth? Fission Theory
Capture Theory The Moon happened to be passing by, and got caught in Earth s gravity. CONS: HIGHLY UNLIKELY!!! The chance of the Moon passing by at *just the right* speed and angle to get caught gravitationally is staggeringly tiny.
Co-creation Theory The Moon and Earth formed side by side at the same time during the formation of the solar system. CONS: Why aren t they more similar?
Collision-Ejection Theory A Mars-sized object collided with a young, molten Earth and knocked off a huge chunk The chunk (and fragments) collected into a ball: voila! The Moon. Accounts for similar heavy elements, but absence of lighter ones.
Greek Titan and mother of Selene, the goddess of the Moon. Theia
BTW We think the Moon is roughly 4.4 Billion years old. Slightly younger than Earth (4.5 Billion), but not by much...
Earth-Moon Relations Gravitational mid-point between Earth and Moon: barycenter Located: 1068 miles below the Earth s surface, in line with the Moon!
Earth-Moon Relations The Moon rotates on its own axis very slowly 27.3 Earth days for one Lunar day! The Moon takes the EXACT SAME amount of time to orbit the Earth once. Result: One side of the Moon is always facing us! Tidal Lock
Far Side vs. Dark Side The Far Side of the Moon The side we NEVER see from Earth, because it s always facing away from us. Heavily cratered, due to facing out into space The Dark Side of the Moon The side that happens to be facing away from the Sun at any particular time. The side of the Moon in shadow.
Tides: How do they work? Inquiring minds want to know?
Tides! The Moon has a significant gravitational pull on the Earth. The oceans get pulled toward the Moon as it orbits around us. The swelling of the oceans in various locations causes the tides.
Tides Awesome British dude explaining how the tides work.?
Spring Tides extreme high and low tides Neap Tides extremely mild high and low tides Tides How often does low and high tide occur each day at a point on Earth? Twice each!
The Moon s Past and Future? Moon is currently moving away from us! By how much? 3.8 cm each year This causes the Earth s rotation to slow down 1/1000 th of a second each century!
Moon s Past and Future? When the Moon first formed: Earth day was only 5 or 6 hours long! Moon was SUPER close and orbited SUPER quickly. Caused HUGE ocean tides, stirring up water & possibly aiding life on Earth