Chapter 1 - PREMIDTERM Flashcards
How old was big bang
12-18 billion years
How old is solar system
5/6 billion
How old are planets
5-4.6 billion
How old is earth
4.6 Billion
What is solar nebula theory?
According to solar nebula theory, condensation of gass resulted in counter clockwise rotation disk of gases and materials. 90% of material formed center, things on outside were called solar nebula
How did earth form? How did earth get its core?
- smaller planets orbited earth at first
- planets grew through series of collisions
- collision between earth and another object (+ heat of collision) gave earth its iron core
What is co-accretion?
Hypothesis of how moon came.
-moon accreted at same time as earth through collisions
What is capture theory?
Moon formed somewhere else in solar system but came close enough to earth to be caught by its gravitational pull and remained in orbit
What is fission theory
earth spun so fast that the moon split off from it, but didn’t get enough speed to leave gravitational pull
What is giant impact theory?
Moon was created by theia hitting earth
What is theia?
Giant body that was hypothesized to hit earth, creating moon
How are waves created? (where does force come from?)
Moon
Is moon coming towards us or further away
Further away
What is the most probable hypothesis of the creation of the moon? Why is this the most probable cause?
Least probable cause? Rank probables causes in order
Theia / Giant impact hypothesis
-the one where theia, giant body, hit earth, creating moon.
-most probable from data of core, composition of moon
FROM MOST PROBABLE TO LEAST PROBABLE
Giant impact, fission, capture, co-accretion
When the earth was created, what was it mainly made out of? what type of material?
Silicates
How did segregation of earths materials work when earth was first created (by impact)?
Early earth was mainly silicates
Lightest material stays on the outside, heaviest material goes to the centre, thus creating the mantle and crust (gravitational segregation)
The impact gave earth more iron and nickel to the earth’s core
Gravitational compression, meteorite impact and radioactive decay increased earth’s temperature and was hot enough to melt the iron and the nickel. While the silicate material went up. This segregated to the centre and thus the homogeneous layer disappeared and there were different layers.
What are terrestrial planets?
inner planets
What are jovian planets?
Outer planets
How many comets hit Jupiter every year?
Gravitational force of Jupiter prevented comets barraging it
Principles of uniformitarianism
Uniformity of: Laws of nature
Processes
rate
state
Principles of uniformitarianism: exceptions
- earths rotation has slowed
- atmospheric composition
- continents and oceans -movement due to plat tectonics
- colonization of land by plants -and animals
What are cycles? Give some examples
Continuous, no beginning and end
-consists of reservoirs, storage tanks
Is earth a closed system?
Earth is considered a closed system compared to universe
What are subsystems of earth? are they open or closed systems?
Atmosphere lithosphere biosphere hydrosphere -all open systems, but earth is a closed system compared to solar system
