Birth Of Earth

Question 1

Explain nebular theory

Answer 1

1. Solar nebula formed
2. Gravity contracted solar nebula
3. Material collected in center
4. condensation sparked nuclear fusion to create photosun
5. Remains formed rotating disk
   - matter cooled and condensed into icy, rocky stuff that collided to form planetismals
6. Collisions and accretion formed protoplanets
7. Protoplanets accumulated most of the debris in their orbit to be planets

Question 2

Solar nebula definition

Answer 2

Rotating cloud of interstellar gases (helium and hydrogen mainly) and dust

Question 3

How did the moon form?

where did most of its mantle and core come from?

Answer 3

collision w/ a Mars-sized body
Ejected material was caught in Earth’s orbit and eventually formed the moon
* with most of its mantle coming from the impactor and its core from the Earth

Question 4

Why do scientists use meteorites to determine the age of the Earth?

composition of meteorites
what do they represent
indication of surface

Answer 4

irons, stony materials, iron-stony represent composition of terrestrial planets
Earth has more iron and nickel than what surface rocks indicate

Question 5

What protects Earth from solar wind? How? what phenomenon is this?

Answer 5

Magnetosphere - solar winds goes through the poles—> northern and southern lights

Question 6

What led to the four seasons?

Answer 6

Tilt of earth from mars-sized body

Question 7

What special type of rock formation did reactions between oxygen and the iron rich ocean produce?

Answer 7

Banded iron formations

Question 8

Relative mass of Terrestrial planets vs Jovian planets

Answer 8

Terrestrial: less than 1 (earth=1)
Jovian: more than 1

Question 9

Number of satellites of terrestrial planets vs number of satellites of Jovian planets

Answer 9

Terrestrial: few
Jovian: many

Question 10

Inclination of orbit of terrestrial planets vs Jovian planets

Answer 10

Terrestrial: larger (earth=0)
Jovian: smaller

Question 11

Polar flattening definition and terrestrial vs Jovian

Answer 11

Measure of how squished a planet is from north to South Pole

Terrestrial: smaller
Jovian: larger

Question 12

Planetismals composition (inner planetismals)

temp

Answer 12

Metals and rocky substances, stuff with high melting temperatures

Question 13

Planetismals composition (outer planetismals) accumulation of this led to

what did it have small amounts of

Answer 13

High percentages of ices - water, co2, ammonia, and methane, small amounts of rocky and metallic debris

Large size and low density

Question 14

Period of revolution definition aka
Terrestrial vs Jovian

Answer 14

How long it takes for a planet to go around the sun

Orbital period

terrestrial: shorter
Jovian: longer

Question 15

Orbital velocity definition
Terrestrial vs Jovian

Answer 15

Speed a planet moves on it revolution
terrestrial: faster
Jovian: slower

Question 16

AVG density terrestrial vs Jovian
How is density measured?

defintion of density

Answer 16

Terrestrial: much larger than 1
Jovian: cluster around 1

Weight per unit volume (g/cm^3)

Question 17

Diameter of Terrestrial vs Jovian

Answer 17

Terrestrial: thousands of miles
Jovian: tens of thousands of miles

Question 18

Period of rotation meaning
Terrestrial vs Jovian

Answer 18

How long it takes to rotate around axis (how long a day is for that planet)

Terrestrial: longer (days)
Jovian: shorter (hours)

Question 19

Interiors of terrestrial planets

core
mantle
crust

Answer 19

large cores of iron and nickel
Rocky mantle and crust

Question 20

Why does Earth have a strong magnetic field?

Answer 20

core is hot enough to undergo convection and rapid rotation

Question 21

Interior of the Jovian planets

core
layers above core for jupiter and saturn, & uranus and neptune

Answer 21

small, rocky/iron core

Jupiter and Saturn: liq. metallic hydrogen (electric currents), liq. molecular hydrogen, gaseous hydrogen/helium, visible clouds

Uranus and Neptune: ices (water/methane), gaseous hydrogen/helium, visible clouds

Question 21

Atmosphere of terrestrial planets vs jovian

Answer 21

terrestrial: co2 and nitrogen, thinner
jovian: thicker, hydrogen and helium

Question 22

Where do airless bodies develop?

Answer 22

warm surface temperatures and weak gravities bc gas particles move faster and don’t stay around bc it can escape gravity

Question 23

where did the outer planets form? and how was this related to solar heating?

Answer 23

temps are low and minimal solar heating allowed gases to condense into ices

Question 24

what are asteroids? size of debris

Answer 24

piles of rubble where fine debris concentrates in in low areas and is surrounded by large boulders

Question 25

what are comets?

Answer 25

collections of rocky material, dust, water ice, and frozen gases

Question 26

where do meteors originate from

Answer 26

debris missed by the sweep of planets during formation, asteroid belt, or comets

Question 27

where did earth’s water come from

Answer 27

asteroids that jupiter sent to earth