Earth And Moon

Question 1

Crust

Answer 1

coolest, least dense

Question 2

Outer core

Answer 2

liquid nickel/iron

Question 3

Inner core

Answer 3

solid nickel/iron, most dense, hottest

Question 4

Earth’s Fragile Atmosphere

Answer 4

Nitrogen 78%, Oxygen 21%, Argon, Water vapor, Carbon dioxide
We essentially live in a nitrogen/oxygen atmosphere.

Question 5

Why is the sky blue

Answer 5

Small particles in the atmosphere scatter shorter (more blue) wavelengths of light easier than longer (more red) wavelengths of light.

Question 6

Greenhouse effect

Answer 6

Water vapor and Carbon dioxide absorb and re-emit infrared radiation, making the average temperature about 260K = 63 degrees

Question 7

Magnetic field

Answer 7

Dynamo hypothesis-

Magnetic field Is produced by fluid metallic layer in the interior of the world

Question 8

Tides

Answer 8

Regular changes in height of ocean levels. Two high tides and two low tides occur each day. Show yearly, monthly, and daily patterns

Yearly- sun
Monthly-moon
Daily-rotation of the earth

Question 9

What causes tide?

Answer 9

The gravitational pull of the sun and the moon on the rotating earth

Question 10

Tidal friction

Answer 10

Earth’s rotation is slowly and the moon is getting farther away

Question 11

Orbit of the moon

Answer 11

Average distance: 384,000km

Time for one orbit: 27.3 days

Question 12

Does the moon rotate?

Answer 12

Yes

If the moon did not rotate, we would be able to see all sides as the moon orbited around us.

Question 13

Properties of the moon

Answer 13

Mass - 1/80 mass of Earth’s
Radius - 1/4 radius of Earth
Density - 3300 kg/m3
Gravity - 1/6 g
Escape velocity - 2.4 km/s

Question 14

Does the Moon have an atmosphere?

Answer 14

No! Escape velocity is too low; gases can easily escape.
Slow erosion - only from impacts
No protection from radiation and impacts
No temperature regulation: Daytime = 400 K = 260 °F
Night-time/shade = 100 K = -280 °F

Question 15

What Is the Moon Made Of?

Answer 15

Light regions - older (~ 4 billion yrs), rich in aluminum Dark regions - younger (3.2-3.9 billions yrs), richer in iron

Question 16

Features on the Moon

Answer 16

Lunar highlands - light regions 
Lunar maria - dark regions, formed by giant impacts

Impact craters 
Rays
Regolith 
Rilles 
Mountains 
Valleys

Question 17

How did the Moon form?

Answer 17

Four competing hypotheses:

Sister/Co-formation - Earth and Moon formed at the same time

Capture - Moon formed elsewhere and was caught by the Earth’s gravity

Daughter/Fission - a rapidly spinning early Earth spun off material that formed the Moon

Giant Impactor - A large (Mars-sized) object hit the Earth and the debris formed the Moon.
=> Most favored hypothesis!

Question 18

Earth’s Interior

Answer 18

Crust, mantle, inner core, outer core