Kahn Academy Earth and Space Science Flashcards
What two variables is Gravity Influenced by?
Mass and the distance between objects
What are Mar’s two moons?
Phobos (fear) and Deimos (dread)
Mars’ atmosphere
Thin atmosphere of carbon dioxide
What is the Oort Cloud?
Space at the very edge of the solar system that is filled with comets made of ice and dust.
How often does Halley’s Comet come near Earth?
Every 75 years
What is Jupiter’s atmosphere made of?
Hydrogen and Helium
How many moons does Jupiter have?
50
How was the Solar System formed?
By a huge cloud of gas and dust 4.6 billion years ago.
Common features of terrestrial planets
Thin atmospheres, solid surfaces, few or no moons, no rings.
Common features of Gas Giant planets
Thick atmospheres, no solid surfaces, many moons and rings
Natural Satellite
Naturally occurring body that orbits a planet.
How long does the moon take to orbit Earth?
27 days
How long does it take for the moon to orbit on it’s axis?
27 days (the same amount of time it takes for it to orbit Earth, hence, the same side of the moon is always facing us)
Waxing Moon
Phases when the moon is growing bigger.
Waning Moon
Phases when the moon is growing smaller
The 8 Moon Phases
New, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, third quarter, waning crescent
New Moon
When the lit side of the moon is facing completely away from Earth.
Lunar Eclipse
When the moon is covered by Earth’s shadow.
Why do lunar eclipses only occur during full moons?
It’s the only time in Earth’s orbit where the Earth is between the sun and moon.
Why isn’t there a lunar eclipse every full moon?
Because the moon’s orbit around Earth is tilted relative to Earth’s orbit around the sun.
This means the moon passes just above or below Earth’s shadow.
How old is Earth’s water?
4.6 billion years old
What percent of water on Earth is Ocean?
95%
Transpiration
Evaporation of water from plants- water is absorbed through plant roots and through transpiration, turns into water vapor and leaves directly through the leaves through tiny pores called stomata and return to the atmosphere.
What force drive evaporation and transpiration?
The sun’s energy
What force drives precipitation?
Gravity
Air masses formed on land tend to have less humidity than those formed over…
The ocean
Air Mass
Large body of air w/ uniform temp and humidity.
Air mass movement…
From areas of high pressure, to areas of low pressure.
Cold Front
Formed when cold air mass moves into a warm air mass. It usually brings cool temperatures, heavy rain, and/or thunderstorms
Warm Front
Warm air mass moves into cold air mass. It usually brings warm temperatures and moderate rain.
Current
The steady flow of a fluid (such as air or water) within a larger body of that fluid.
Prevailing winds
Air currents that blow mainly in one direction and caused by the uneven heating of Earth’s surface.
What causes ocean surface currents?
Prevailing winds blowing across the ocean.
Coriolis Effect
The curve of surface currents and prevailing winds due to Earth’s rotation.
Which way do northern hemisphere currents curve?
To the right
Which way do southern hemisphere currents curve?
To the left
Gyre
Giant rotating systems formed by surface currents of the ocean connecting.
How deep into the ocean do currents that drive gyres extend?
About 1km down into ocean and help move water all around the globe.
Water is good at holding heat from the sun, causing gyres not to just move water but…
Heat energy
How does warm and cold water move between the equator and poles?
Warm water moves from the equator to poles and cold water moves from the poles to equator.
Water density is effected by these two variables…
Temperature and salinity
Denser water is…
Saltier and colder, therefore it sinks like cool air
Less dense water is…
Warmer and less salty, so less dense water rises
Overturning Circulation
Vertical currents are connected by horizontal currents at the surface and deep currents (vertical)
Climate
Long term pattern of weather in a particular region.
Latitude
Measuring north and south on the globe, with the equator being zero degrees (90 degrees north, 90 degrees south)
Why do regions at higher elevations, like mountains, tend to have lower average air temperatures than areas of low elevation?
As air rises from lower to higher elevations, it expands and cools, hence cooler weather.
While water heats and cools slowly, land…
Land is faster in temperature change.
Why do climates tend to be more mild near oceans and lakes- with less seasonal variation?
Large bodies of water help moderate air temperatures.
Rain shadow
Area of reduced rainfall behind a mountain range. In a rain shadow, the climate is warmer and drier compared to the climate on the other side of the range,
Igneous Rock
When molten rock cools and becomes solid. Igneous rocks make up more than 90% of Earth’s crust.
Magma
Molten rock existing below Earth’s surface.
Magma tends to cool slowly underground, which gives it time for…
The elements in it to form large crystals.
Lava
Molten rock that flows above the ground
Lava tends to cool…
Quickly
Weathering
When water, weather, wind, and other physical forces chip away at a rock
Sediments
Rock particles chipped off a rock due to weathering
Erosion
Transports sediment from one place to another
Deposition
Drops sediment in a new location
Sedimentary rock
Formed when sediment is compacted and cemented.
Lithification
The process of sediments compacting to produce sedimentary rocks
Metamorphic rocks
Form when existing rocks are exposed to intense heat and pressure. Can be formed from igneous, sedimentary, and other metamorphic rocks.
Geologic timescale
Breaks up all of Earth’s history into units called eons and eras
Strata
Sedimentary rock layers
Law of Superposition
Layers of strata at the bottom are older than layers at the top.
Law of cross cutting relationships
When two geologic features cross or intersect, the feature that cuts through the other is younger.
Plate Boundary
A place where two plates meet
Index Fossils
Fossils that are only found on a specific section of the geologic timescale
The first single cellular life formed how long ago?
3.8 billion years ago
The first multicellular life formed how long ago?
600 million years ago
Fault
A crack in Earth’s crust
Intrusion
Body of igneous rock formed in Earth’s crust
Lithosphere
Made up of Earth’s crust and upper part of the mantle
Tectonic plates
Broken up pieces of the lithosphere
Asthenosphere
Section of the mantle just below the lithosphere.
How long ago did pangea break apart and drift into the current continents?
200 million years ago
Evidence of continental drift
- Matching or complimentary coastlines of continents
- Fossils of the same species on different continents.
Plate Interaction Types
- Convergent
- Divergent
- Transform
Convergent boundary
One plate sliding under the other and pushing it up.
Divergent Boundary
Two tectonic plates move apart and create different kinds of landforms like rift valleys and mid ocean ridges
Transform Boundary
When two plates slide past each other but cause friction and builds pressure and release causes earthquakes.
Continental crust contains lots of…
Granite
Oceanic crust contains lots of
Basalt
Which type of crust is denser: oceanic or continental?
Oceanic crust
The high density of oceanic crust causes oceanic plates to sink into the asthenosphere a bit more than…
Continental plates
Compaction
When sediment is deposited in a new location and spreads out to form a layer. As more layers are created, the layers underneath them become squished together.
