The Moon

Question 1

what is the dark areas known as?

Answer 1

maria (singular mare)

Question 2

what are the two types of general surface?

Answer 2

1. lowlands, mostly maria

2. highlands, vast mountainous regions

Question 3

what is the size of the moon compared to earth?

Answer 3

1.2% mass of earth

one quarter the diameter

Question 4

what is the moons albedo?

Answer 4

low, 7%

Question 5

what are lowlands?

Answer 5

grey plains that occupy 15% of moons surface. expanses of volcanic lava

Question 6

Where do earth-facing maria lie between?

Answer 6

2 and 5km below mean radius of moon

Question 7

why are there very few maria on far side?

Answer 7

earths gravitational effects on moon

Question 8

why are mare young by lunar standards?

Answer 8

have less craters than elsewhere, 3-3.9 billion years old.

Question 9

what are the typical mare features?

Answer 9

sinuous rills: lava channels, often originating from craters in high regions of maria and flow into lower lying areas

wrinkled ridges: result from folding in the surface layrrs of maria

dome-like features: with summit craters

Question 10

How old are highlands?

Answer 10

most ancient: 4.5 billion years old, as old as moon

higher albedo than mare

Question 11

what are the features of highlands?

Answer 11

extensively cratered, less dense than mare, remnants of lunar crust.

no mountain ranges, main lunar boundaries are circular maria

Question 12

what dominates the entire surface of the moon?

Answer 12

craters

Question 13

what is the processes of craters being formed?

Answer 13

1: missile strikes surface, shock waves sent into target and projectile itself. projectile vaporizes, and material ejected at high velocity.
2. next stage material thrown out at lower velocity, excavating crater, plume of material is ejected from crater
3. ejected material falls back to surface and rum of crater formed by uplift

Question 14

what is the Regolith?

Answer 14

surface of moon covered by layer of dust and broken rock, overlying solid bedrock

loose, footprints last long time.

Question 15

how is regolith created?

Answer 15

meteoric bombardment

Question 16

does moon have atmosphere?

Answer 16

no, escape velocity too low (2.4 km/s)

Question 17

what is density?

Answer 17

3.3 g/cm^3

Question 18

how much smaller is the core of moon to earth?

Answer 18

smaller fraction (20%), than earth (50%)

Question 19

how thick is the crust?

Answer 19

50-100 km at appolo sites, thicker on far side where no maria

Question 20

composition of mantle?

Answer 20

rigid- no plate tectonics

Question 21

composition of core?

Answer 21

partially molten at present , heat flow from interior, radioactive decay

Question 22

why is there a lack of large molten core?

Answer 22

no dynamo, no weak overall magnetic field

Question 23

why is the surface as it was formed?

Answer 23

no tectonic activity/erosion, only altered by lava flows and bombardment

Question 24

how as moon formed?

Answer 24

grazing impact by mars sized object. large body was differentiated with iron core. partially vaporised by impact. bodys iron poor mantle formed hot disk around earth, which coalesced to form moon. result moon with large angular momentum and low overall iron abundance, low content of volatile elements.