Download The Moon: NOTES

The Moon: NOTES
Our Closest Neighbor
• The Earth’s only _______________________ satellite
• Orbit around the earth is an ellipse
• Average distance from the earth to the moon is 384,403 km (238,857 miles) –
__________ times the diameter of the earth
• Diameter of 3,474 km, __________ of the earth
• Gravity _______of the earth
The Moon is huge!
• ___________ largest moon in the solar system
• Largest moon compared to ___________ size!
• The other 4 largest moons are all moons of Jupiter and Saturn and are thus tiny
compared to their parent planets. The moon is absolutely huge compared to the
Earth and this causes a lot of unique effects like the tides and solar eclipses.
Everyday is a birthday on the moon!
• The revolution (one moon ________) around the earth – ________ days
• The rotation (one moon _______) is exactly the same!
• The result: we always see the same side of the moon!
• Having such a large moon has resulted in another strange affect. The Earth and
Moon tug on each other in such a way that the moon’s orbital period (its year) is
the same length as its rotational period (its day)!
So what does the far side look like?
• No one knew until ____________ when it was first photographed by the
Russians.
• Has ___________ features than the side facing us.
• Note: far side does not equal dark side!
On the Moon…
• Explorations of the moon have been extensive, culminating with the Apollo
mission and the first and only time a human has walked on another celestial body.
The history leading up to this triumph could take up a class in its own, so I’ll just
focus on what we found when we got there.
• No atmosphere
– Temperature: there is no way to retain heat or shield from sun rays.
• Daytime high of _________ F
– Nighttime low of _________F
• Extreme temperature variation from day to night
– Sky is always ___________
– No _______________
– It’s very dusty, but the dust stays still because there is nothing to move it
around.
Surface Features
• Maria = ____________ in Latin, thought by the ancients to be oceans on the
moon.
• Now known to be dried _______________ flows from impact craters.
• When there were impacts on the young moon, lava was able to flow up
from the center to fill them. This can’t happen now, since the moon is
cold and solid.
• Highlands = the ________________, made of lighter rock than the maria
• Covered in craters
• Mountains created by impacts
• The highlands, predictably, are higher areas than the maria, where lava
did not flow. The highlands are covered in impact craters and have
mountains created by those craters. Though the moon can still be hit
by meteors, most of the craters were formed when the solar system
was still young and debris was flying everywhere. Most of that debris
hit something or was thrown out of the solar system within a few
million years.
Craters!
• Very old impacts from the beginnings of the solar system
• Concentrated on the ___________ side of the moon
• Was the Earth also bombarded like this early in the solar system?
Aww, what a cute baby…moon?!
• Giant Impact Theory
– A Mars sized object hit the young Earth, breaking off a piece
– Currently the leading theory
• Fission Hypothesis
– Moon broke off of young Earth that was spinning really ______________
• Capture Theory
– Moon was captured by Earth’s ______________________ as it passed by
• Co-formation
– Moon formed at the _______________________as the Earth
Tomorrow: Notes on Moon Phases
Thursday: Notes on Eclipses
HOMEWORK:
-- work on journal (have all the vocabulary worksheets been completed? are all pages
glued in correctly?)
-- work on this week's packet (the moon)
-- study for quiz on asteroids and comets for Friday