Lecture 1-8

Question 1

What is a planet?

Answer 1

Cold object that orbita around a central luminous start

Question 2

What is a Planetary body?

Answer 2

General term for any body orbiting a star includes planets and their natural satellites/moons

Question 3

Terrestrial (Inner) planets

Answer 3

Relatively small, rocky (“Earth-like”) bodies closest to the sun
↳ moon is studied as a terrestrial planet

Question 4

General planet info

Answer 4

• Mercury
  ↳ larger than earths moon & closes to sun
• Venus
  ↳ 2nd closest planet & shrouded by clouds
  ↳ lots of craters and mountain belts
• Earth
  ↳ lots of plate tectonics, erosion, has life along with atmosphere
• Moon
  ↳ orbits earth
• Mars
  ↳ very thin atmosphere
  ↳ erosion by water, lots of volcanoes & valleys

Question 5

Asteroid

Answer 5

small rocky or metal-rich planetary body orbiting the sun

Question 6

Asteroid belt

Answer 6

• region between the orbits of Mars and Jupiter where most asteroids are found
• asteroids range from 1 - 1000km in diamerter

Question 7

Gas Giants (outer Planets)

Answer 7

Large planets that have a deep atmosphere and no solid surfaces
↳ icy/rocky

Question 8

Comets

Answer 8

small, ice rich bodies which formed at the outer edges of the solar system

Question 9

Neptune & Uranus

Answer 9

• Both are gas and ice rich
• Have icy moons

Question 10

The three main tock types

Answer 10

Igneous, Sedimentary, and Metamorphic

Question 11

Law of Superposition?

Answer 11

Each layer of sediment is older than the layer above it and younger than the layer below it

Question 12

Law of Cross-cutting Relationships?

Answer 12

If a fault or other body of rock cuts through another body of rock then it must be younger in age than the rock through which it cuts

Question 13

Law of Inclusions?

Answer 13

One rock included in another is older than the rock that includes it

Question 14

Law of original horizontality

Answer 14

Sedimentary layers are deposited horizontally

Question 15

Crust

Answer 15

The outermost layer, on top of the mantle

Question 16

Mantle

Answer 16

It has upper and lower sections and includes the asthenosphere, iron, and magnesium-rich silicate minerals

Question 17

Asthenosphere

Answer 17

The top part of the upper mantle where it is plastic, and partly molten

Question 18

Lithosphere

Answer 18

includes the rigid part of the mantle and the overlying crust, rides on the plastic asthenosphere

Question 19

The three ways we know what the interior of the Earth looks like

Answer 19

Density, Seismic data, Meteorites

Question 20

Main geologic processes active on Earth today

Answer 20

Tectonics, volcanic activity, mass wasting, water, wind, ice -> erosion and deposition of sediment, impact crater, life

Question 21

Fusion

Answer 21

The combination of two or more nuclei to form a different, heavier, element; the by-product is radiation

Question 22

What Keeps a Star together?

Answer 22

• Gravity attempts to make the star collapse
• High gas pressure opposes gravity

Question 23

Supernova

Answer 23

The cataclysmic explosion of a star, as a result of internal nuclear reactions

Question 24

Nebula

Answer 24

Dust in space with a density of 1,000 gas molecules/10cm^3

Question 25

Gravitational Collapse

Answer 25

When molecules are concentrated, attracted to each other; may be triggered by a nearby supernova

Question 26

T Tauri stars

Answer 26

stars that are similar in mass to the Sun, but only about 1 million years old

Question 27

Proplyds

Answer 27

disks of dust and gas around young stars; contraction of “protoplanetary disks"

Question 28

Meteorites

Answer 28

extraterrestrial rock that's fallen through our atmosphere

Question 29

Refractory

Answer 29

materials that form solids at very high temperatures

Question 30

Volatile

Answer 30

materials that condense/solidify at very low temperatures

Question 31

Planetesimal

Answer 31

Small solid bodies, ~100km across, that formed from grain-to-grain accretion of dust

Question 32

Accretion

Answer 32

Solids come together to form larger objects through gravitational attraction and collisions

Question 33

Differentiation

Answer 33

The separation of materials in a planetary body according to density and chemical affinity

Question 34

Conduction

Answer 34

The vibrational energy of an atom is transferred to adjacent atoms

Question 35

Convection

Answer 35

Warm material expands and moves upwards, displacing cooler, denser materials downwards

Question 36

Radiation

Answer 36

The emission of electromagnetic waves from a hot body’s surface to its surroundings

Question 37

Law of Cross-cutting Relationships for impact cratering

Answer 37

If an impact crater, fault, or body of rock cuts through another body of rock then it must be younger than the rock through which it cuts

Question 38

Three things that must be explained by any model for how the solar system was formed

Answer 38

- The planets orbit in the same plane - They orbit the Sun in the same direction - The Solar System is zoned from rocky inner planets to gas-rich outer planets to ice-rich comets

Question 39

Why the Moon always shows the same side to the Earth

Answer 39

The period of rotation and period of revolution are exactly the same

Question 40

Two surfaces on the Moon that can be easily seen from Earth

Answer 40

- Maria (smooth surfaces) - Terrae (cratered highland)

Question 41

Crater sizes on the moon

Answer 41

- 20 to 200km diam ↳ have central peaks - crater > 300km diam ↳ called multi ring basins & spacing of rings increases outward

Question 42

What is KREEP

Answer 42

KREEP is a component found in soils, breccias and impact melts

Question 43

Fire fountaining

Answer 43

Volcanic activity on the Moon, it creates Lunar Glass Beads

Question 44

Anorthosite

Answer 44

Most abundant and oldest rock type

Question 45

Breccia

Answer 45

A rock made up of angular fragments of other rocks ↳ more basalts

Question 46

Regolith

Answer 46

- Mixture of rock fragments - Formed during micrometeorite impacts;

Question 47

Explain why mare basalts can flow such great distances on the Moon

Answer 47

They contain more iron and less silicate and aluminum, which causes lunar basalts to have a lower viscosity

Question 48

List the main observations that any model for the formation of the Moon must explain

Answer 48

- size of the moon relative to earth - The low bulk density/size of its iron core and its composition - Moon has little water and is depleted in other elements - it's orbit

Question 49

Giant Impact Hypothesis

Answer 49

- The giant impact hypothesis proposes that the Moon formed from debris ejected during a collision between the early Earth and a Mars-sized protoplanet around 4.5 billion years ago.

Question 50

The major discoveries made by the Lunar Reconnaissance Orbiter mission

Answer 50

evidence of water on the Moon, Moon caves, map of the lunar south poles, more topography, temperature map

Question 51

Describe how the crystallization of a magma ocean explains the anorthosite composition of the Moon’s crust

Answer 51

- pyroxene and olivine in the magma sink and the anorthosite (lighter mineral) floats