Formation of the Solar System + Earth

Question 1

Solar Nebular Disk Model Consists of:

Answer 1

Nebula (cosmic dust and gasses) and nearby star which goes Supernova (massive explosion at end of lifecycle)

Question 2

How is a disk and then protostar formed

Answer 2

supernova releases massive wave of energy –> spins nebula –> flattens into disk shape –> creates a gravitational pull –> mass pulled into center of disk –> pressure and temperature increases –> forms a protostar

Question 3

How is a star formed

Answer 3

more mass and pressure causes protostar to undergo FUSION –> creates a star

helps in planet formation by preventing loss of nebula material, solar winds, gravity

Question 4

How are planets formed (accretion and planetesimals)

Answer 4

Accretion (many small pieces brought together)

Planetesimal (objects already formed by accretion that are large enough to generate their own gravity)
these planetesimals accrete together and grow even bigger

Question 5

Importance of Solar Winds

Answer 5

waves of charged particles interact with other atoms and structures in new solar system

Metals and rocks were not moved very far by solar winds – formed small planets

Light materials pushed very far by solar winds (past frost line) - formed big gas planets

Question 6

Formation of Earth and when

Answer 6

4.56 - 4.53Ga
gasses to form the atmosphere pulled in by gravity, no oxygen
formation of the metallic core
mantle solidfies (4.53Ga)

Question 7

Formation of the Moon

Answer 7

4.5 billion years ago
Theia collided with developing Earth
Theia destroyed
debris formed the moon
Slowly moving away from Earth

Question 8

Important processes after the moon formation (4)

Answer 8

Plate tectonics, magnetic field, outgassing as rock cools, bombardment

Question 9

Formation of Plate Tectonics

Answer 9

Possible impact that broke up solid crust which began process of recycling and movement

Believed to be essential to life

Question 10

Formation of Magnetic Field

Answer 10

Interaction between solid metal core and liquid outer core

deflects solar winds, protects atmosphere

Question 11

Habitable Zone factors

Answer 11

Right mass of star
Right distance from star where liquid water and gaseous CO2 can exist
Gravity - retain atmosphere and ocean
Right planetary mass - for plate tectonics and magnetic field
Jupiter factor - clears out comets
Large Moon - stabilizes tilt, creates tides for life
Plate Tectonics - internal heat bc of big enough

Question 12

When is carbon-dating used

Answer 12

shorter term dating of mainly organic samples

Question 13

Outgassing

Answer 13

atmosphere generated by
1) cooling rock releasing gases
2) continued volcanic activity
3) elements from comet impacts (water derived from comets)

Question 13

When was the Late Heavy Bombardment? - add more

Answer 13

drop in bombardment rates of asteriods and comets 4.4 - 3.8 Ga

Question 14

Radiometric Dating + Half Life

Answer 14

Radioactive isotopes have half life (time needed for a quantity of a substance to reduce by half)
also, ratio of old parent isotopes to newly formed daughter isotopes

Question 15

When is Relative-Age dating used

Answer 15

For weathered rocks
Inferring age of material by looking at surrounding rock which can be dated radiometrically

Question 16

Inside of Earth Layers

Answer 16

Inner core - solid ball of iron and nickel
Outer core - liquid layer
Lower mantle and upper mantle - composed mainly of rock (solid)
Crust - where life exists
composition determined by interpreting timing of seismic waves