Is Earth Unique?

Front 1

age of universe

Back 1

15 billion years old

Front 2

age of solar system

Back 2

4.6 billion years ago

Front 3

composition of interstellar dust and cloud

Back 3

gas, plasma, dust and hydrogen

Front 4

composition of sun

Back 4

hydrogen and helium

Front 5

what kind of star is the sun / how common is this type

Back 5

G type star main sequence star (yellow dwarf). common among the universe but have 10 billion years of life

Front 6

why is the mass of a star its most important property

Back 6

Long enough lifetime. Not too much ultraviolet

Front 7

where did the heavy elements come from to form rocky planets

Back 7

fusion, the fusing together of lighter atoms to produce heavier ones, it occurs in the interior of stars towards the end of their lives

Front 8

where in the solar nebular do rocky planets form

Back 8

in the inner part of the protoplanetary disk, within the snow line, where the temperature is high enough to prevent condensation of water ice and other substances into grains.

Front 9

where do icy planets form

Back 9

outter part of protoplanetary disk at far distances and low temperatures

Front 10

how do planets and moons form

Back 10

gas and dust cloud form nebula, nebula forms star and planets.

Front 11

why is the solar system a disk

Back 11

Because a mass of interstellar material became dense and cool enough to grow unstable and gravitationally collapse into itself to form a flattened rotating cloud

Front 12

why do planets and moons rotate

Back 12

In a system where the angular momentum is not precisely zero, things will rotate and revolve.

Front 13

what elements are in the core of the Earth

Back 13

nickel, iron

Front 14

what elements are in the mantle and crust of the Earth

Back 14

sodium magnesium aluminum silicon

Front 15

what elements are in the atmosphere of the earth

Back 15

nitrogen, oxigen, water vapor and carbon dioxide

Front 16

where did Earth’s oceans and atmosphere come from

Back 16

oceans formed from outgassing H20 vapor and salt from chemical interactions with land (crust), crust is formed by volcanism and cooling of magma

Front 17

how long to form Earth

Back 17

between 4.6 by and 3.9 by

Front 18

what was Earth like in first 100 My

Back 18

it was very violent, heat build up due to impacts and co2 greenhouse environment

Front 19

how was the core formed

Back 19

the heavy elements moved to the core (iron and nickel)

Front 20

what was the early atmosphere

Back 20

it was formed of carbon dioxide, very hot

Front 21

where did the water originally come from in the solar nebula

Back 21

from comets and asteroids that brought water and carbon. steam condensed to form oceans

Front 22

was Earth hotter in the past (why?)

Back 22

lack of oxygen

Front 23

was the Sun cooler in the past (why)

Back 23

yes, because it was burning with less energy than today and it had to penetrate a poisonous, turbulent atmosphere

Front 24

how did Earth acquire the volatiles (components that normally freeze at very low temperatures)

Back 24

from comets and asteroids

Front 25

how long before first evolution of organisms

Back 25

3.8 to 3.9 billion years ago

Front 26

what did the Archaean Earth look like

Back 26

Extreme environments

Front 27

what is origin of banded iron formations

Back 27

rusted oxygen

Front 28

why do banded iron formations disappear from geological record at end of the Precambrian

Back 28

all iron had been oxidized

Front 29

what is the length of the Precambrian era

Back 29

from 4.5 by to 4.8

Front 30

what is a snowball Earth event and how does it start / end

Back 30

Earth's surface became nearly or entirely frozen over at least once during three periods between 650 and 750 million years ago.

Front 31

what does a snowball earth event persist

Back 31

glaciation

Front 32

how were snowball earth events detected in the geological record

Back 32

they leave physical evidence: boulders, scour marks on rocks and tillite

Front 33

what effect would a snowball Earth event have on organisms

Back 33

prokaryotess would retreat to undersea locations or into the crust and eukaryotes would die off due to changed geochemistry, surface temperature

Front 34

why would diversity increase after a snowball event

Back 34

it stimulates inordinately rapid evolution among the newly evolved animals, it isolated various populations which diversified phyla that emerged at the other end of the snowball earth events

Front 35

what are the 3 domains that combine to form the Tree of Life

Back 35

Bacteria, Archaea and Eukaryotes

Front 36

which domain has evolved into great complexity

Back 36

Eukaryotes

Front 37

how do prokaryotes and eukaryotes differ in cell design

Back 37

prokaryotes lack a cell nucleus or any membrane-enclosed organelles, eukaryotes are more complex

Front 38

what is the big advantage of sexual reproduction in organisms

Back 38

perpetuation of life

Front 39

what is the role of extremophiles in Earth’s history

Back 39

it favors the deep sea vents for the origin of life, more protected from lethal surface environmental conditions

Front 40

name some locations where extremophiles exist today

Back 40

hot springs (yellowstone)
mid-ocean ridges
within earth's crust

Front 41

what was the importance of the discovery of extremophiles

Back 41

it suggests that widespread primitive life is possible in harsh environments

Front 42

what was the essential role of cynaobacteria in the Precambrian

Back 42

the formation of oxygen as a consequence of their photosynthetic activity

Front 43

what kind of organisms leave fossils

Back 43

skeletonized organisms

Front 44

what are fossils

Back 44

A remnant or trace of an organism of a past geologic age

Front 45

when did the number of fossils suddenly appear in great numbers in Earth’s history

Back 45

latest precambrian, beginning of cambrian

Front 46

what are Ediacarans

Back 46

Ediacarans are a highly distinctive assemblage of fossil organisms, apparently all marine.

Front 47

what was the largest type of creature that evolved during the Precambrian explosion

Back 47

trilobites

Front 48

what is the essential non-gaseous element that is the basis if life on Earth

Back 48

DNA

Front 49

what are the main elements that form living tissue in modern organisms

Back 49

RNA and DNA

Front 50

what substance must be in liquid form for complex life

Back 50

water

Front 51

what compounds are the greenhouse ‘gases’

Back 51

water vapor, carbon dioxide, methane, nitrous oxide, and ozone.

Front 52

what would be the critical spectral signatures of a planet with organic life

Back 52

Ozone, CO2, and H20 in the atmosphere

Front 53

what would happen to the Earth’s atmosphere if it were not replenished by plants

Back 53

It would lack oxygen

Front 54

why do greenhouse gases cause atmospheric warming

Back 54

increasing concentrations of greenhouse gases resulting from human activity such as fossil fuel burning and deforestation

Front 55

how does the carbon cycle work

Back 55

Rotation of carbon from the atmosphere
The terrestrial biosphere, which is usually defined to include fresh water systems and non-living organic material, such as soil carbon.
The oceans, including dissolved inorganic carbon and living and non-living marine biota,
The sediments including fossil fuels.
The earth's interior, carbon from the earths mantle and crust is released to the atmosphere and hydrosphere by volcanoes and geothermal systems.

Front 56

what does oxygen do to minerals and elements

Back 56

oxidizes them

Front 57

Formation of Earth

Back 57

2.5 by

Front 58

First extremophiles

Back 58

4 by

Front 59

End of bombardment

Back 59

3.9

Front 60

Evolution of organisms

Back 60

3.9 - 3.8

Front 61

First organisms

Back 61

3.6

Front 62

first glaciation

Back 62

3.5

Front 63

secong glaciation

Back 63

0.6

Front 64

Cambrian explosion

Back 64

0.55