Ch 7+8 Flashcards
Order of Mass of Members of the Solar System
Sun, Jupiter, Comets, All Other Planets + Dwarf planets, Moons + Rings, Asteroids, Cosmic Dust
Which planets were known to the ancients?
Mercury, Venus, Mars, Jupiter, Saturn || Uranus + Neptune after invention of telescope
What are the terrestrial planets?
The inner planets: Mercury, Venus, Earth, Mars
What are characteristics of the terrestrial planets?
- Composed primarily of rock & metal
- Have solid surfaces that bear the records of their geological history via craters, mountains, and volcanoes
What are the jovian / giant planets?
Jupiter, Saturn, Uranus, Neptune
What are characteristics of the jovian planets?
- Do not have solid surfaces where explorers could land
- Are more like vast, spherical oceans with smaller, dense cores.
- All have rings and moons.
How many known moons are there?
180
What are asteroids?
Rocky bodies that orbit the Sun like miniature planets, mostly in the space between Mars and Jupiter
What are comets?
Small bodies composed mostly of ice, made of frozen gases such as water, carbon dioxide, and carbon monoxide
What is a meteorite?
A meteor that has struck the ground.
How old is the universe?
13.8 billion years old
What is the chemical make-up of Jupiter & Saturn?
75% hydrogen and 25% helium
What are the cores of Jupiter & Saturn made up of?
Heavier rock, metal, and ice – because under the force of gravity, heavier elements sink toward the inner parts of the planet
What does Mercury have the greatest proportion of?
Metals (Earth has lowest)
What are compositions of Earth, Venus, Mars?
1/3 iron-nickel or iron-sulfur combos, 2/3 silicates || chemistry said to be oxidized
Solar Nebula
The cloud of gas and dust from which the solar system formed.
Differentiation
Gravitational separation of materials of different density into layers in the interior of a planet or moon
Earth’s Diameter
12,760 km
Elemental Composition of Earth
Iron, Silicon, Oxygen
Layers of the Earth
Crust, Mantle (largest), Core, Inner Core
Moon Crust Composition
> Oceanic (55%) – typically consisting of volcanic rocks called basalt
Continental (45%) – composed of granite
Igneous Rocks
Any rock that has cooled from a molten state (ex. all volcanically produced rock)
Sedimentary Rocks
Made of fragments of igneous rock or the shells of living organisms deposited by wind or water and cemented together without melting (ex. sandstones, shales, limestones)
Metamorphic Rocks
Produced when high temperature or pressure alters igneous or sedimentary rock physically or chemically
Primitive Rock
The original material out of which planetary system was made – (comets, asteroids, small planetary moons)
To detect oil & natural gas on Earth…
Set charges inside Earth like seismograph to listen to echoes
How many years old is the sun?
4.6 billion years
Plate Tectonics
- A theory that explains how slow motions within the mantle of Earth move large segments of the crust, resulting in a gradual “drifting” of the continents as well as the formation of mountains and other features
- On Earth’s crust + Upper mantle
Convection
- A process by which heat escapes from the interior through the upward flow of warmer material & slow sinking of cooler material
- Provides power to move the plates
What are the 4 basic kinds of crustal plate interactions?
(1) They can pull apart
(2) One plate can burrow under another
(3) They can slide alongside each other
(4) They can jam together
Rift Zones
Where plates pull apart (ex. central African rift)
Subduction Zone
Where on plate burrows under another (ex. deep Japan trench along coast of Asia)
Fault Zones
Where crustal plates slide parallel to each other (ex. San Andreas Fault in Cali)
Mountain Building
When plates jam together, raising other folds to heights of many kilometers then its’ rocks are subject to erosion by water and ice.
Volcanoes
Mark locations where lava rises to the surface from Earth’s mantle at plate boundaries
What is the atmosphere pressure at sea level?
1 bar (term comes from same root as barometer, used to measure atmospheric pressure)
How much is a bar of pressure?
Each square centimeter of Earth’s surface has a weight equivalent to 1.03 kilograms pressing down on it
Total Mass of Earth’s Atmosphere
5*10^18 kilograms
Layers of Atmosphere (Low to High)
- Troposphere
- Stratosphere
- Ozone
- Mesosphere
- Ionosphere
Atmosphere Composition at Earth’s Surface
78% Nitrogen, 21% Oxygen, 1% Argon & traces of water vapor & CO2
Volatile Materials
Those that evaporate at a relatively low temperature
Weather
Name given to the circulation of the atmosphere
Climate
Effects of the atmosphere that last through decades and centuries
Snowball Earth
Not certain, but about a billion years ago, the entire ocean froze over
What do the patterns in rocks on Earth tell you?
Earth’s magnetic fields have switched (N–S) many times
At what speed to Earth’s continental plates / year?
4-5 cm / year
Atmosphere of early Earth
abundant in CO2 and some methane but no oxygen gas
Blue-Green Algae
Early life form on earth that takes CO2 and releases O2 as a waste product
Greenhouse Effect
CO2 acts like a blanket trapping heat in the atmosphere and preventing flow back to space. More CO2, higher temp on Earth’s surface
Consequences of Greenhouse Effect
- Floods & Droughts
- Extreme weather
- Difficulty growing crops
- Destroys environments for animals
- Rising sea level
Names of Famous Earth Craters
- Meteor Crater (Arizona)
- Uuarkziz Impact Crater (Algerior)
Cretaceous Period
- Period marked by mass extinction / more than half of species on our planet died out
- Took place 65 million years ago
