TAKS objective 5 Earth and Space Systems

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TAKS objective 5Earth and Space Systems

• Middle School Science
• Science TAKS Need to Know

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Changes in the Earth over time
Weathering- the process of rocks being broken
down into smaller pieces.
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Two types of Weathering

• Mechanical
• Rocks break into smaller pieces by physical means
  
• Water, ice, wind, gravity, organisms changing
  temperatures

• Chemical
• Rocks break into smaller pieces by chemical
  reactions Air, water, acid salts react with
  minerals in rocks to form new substances

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Erosion
Destructive

• The movement of particles from one location to
  another is erosion
• Weathered particles of rock are transported by
  gravity, living organisms, water, glaciers wind.

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Deposition
Constructive

• The settling (depositing) of eroded particles as
  sediments wherever they are transported by wind
  or water.

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Rock Cycle
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Sedimentary
Igneous
Metamorphic
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Plate Tectonics
Plate tectonics explains the movement of large
sections of Earths crust called tectonic plates.
The force behind tectonic plate movement is
thought to be currents of magma flowing in
Earths mantle.
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Plate boundaries

• Tectonic plates slowly collide against one
  another along plate boundaries. Sections of the
  plates may break off and be pushed down, up, or
  to the side. Mountain ranges, ocean trenches,
  earthquakes volcanic activity are all common
  along plate boundaries.

Pacific Plate is the largest
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San Andreas fault
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• All the land that drains into a specific body of
  water.
• Groundwater and surface water both contribute to
  the water in a watershed.
• Surface water becomes groundwater by soaking into
  the sand and soil or by traveling through cracks
  in rock.

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Two important ways that oceans affect climate on
land

• Land heats up faster than water because land has
  a lower specific heat than water does. This
  causes the air over land to heat faster than the
  air over water. The warm air rises, starting a
  convection current that pulls air toward land
  from the ocean. This keeps air over the land
  from getting too hot and brings moist ocean air
  inland.
• Warm air holds more water vapor than cold air
  does. When warm, moist air is cooled, clouds
  form and can produce precipitation. This warm
  air can be cooled by rising into the colder upper
  atmosphere, by moving over cold ocean or lakes,
  or by mixing with colder air. (Ex. Front
  boundary- the edge where cool, dry air meets
  warm, moist air. Often causes stormy weather)

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Nitrogen Cycle
Nitrogen changes back forth from nitrogen gas
to the nitrogen compounds used by plants
animals.
Nitrogen is passed from plants to other organisms
through food webs in the ecosystem. Once plants
animals use the nitrogen it returns to the
atmosphere as a gas, completing the cycle.
Some fertilizers contain nitrogen compounds
because plants need nitrogen to grow. Though
there is plenty of nitrogen gas in the
atmosphere, plants cant use this form. In
nature nitrogen can be changed from a gas to a
form that plants can use by lightning or by soil
bacteria and fungi in a process called nitrogen
fixation.
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Problems if too much Nitrogen in environment
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Carbon Cycle
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Effects of carbon on environment
One of the biggest ways humans affect the carbon
cycle is by burning fossil fuels. Burning fossil
fuels transforms carbon into carbon dioxide.
Higher levels of carbon dioxide cause the
atmosphere to hold more heat energy. This may be
the cause of warmer temperatures measured in
recent years on Earth. (Called The Greenhouse
Effect) This could affect the climate in many
places. The kinds of plants and animals in these
climates may change if the warming continues.
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Without the carbon and nitrogen cycles, there
would be no life on earth!
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Catastrophic events affect the earth
Earthquakes
Floods
Meteorite crater
Volcanoes
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Ways humans affect the earth

• Two common forms of pollution
• Gases released into the atmosphere
• Chemicals that are carried by water into a
  watershed

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Humans can cause extinctions

• Human can change
• The quality of the air, water soil we use
• Ecosystems by removing plants animals by
  introducing new species, such as invasive plants
  pets
• Invasive species dont naturally live in the
  ecosystem where they are introduced.
• Invasive species compete with/or drive out native
  species (species that live naturally in an
  ecosystem)

FIRE ANTS- invasive species- accidentally
introduced to North America from South America.
They have few predators in NA aggressively
attack kill many kinds of native plants
animals. They have upset the balance of
ecosystems in many southern states.
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Renewable
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Non renewable
Fossil Fuels
Natural Gas
Oil
Coal
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Inexhaustible
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Eclipses
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Solar eclipse
When the moon is aligned so that its shadow falls
on Earths surface, the suns light is blocked
from reaching part of the Earth. Called solar
eclipse because its the sun that is being
blocked from our view.
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Lunar Eclipse
A lunar eclipse occurs when Earth blocks sunlight
from reaching the moon. This puts the moon in
Earths shadow.
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4 main Phases of the Moon
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Moon phase diagram
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Moons Revolution Rotation
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Seasons
Have you ever noticed that the sun travels lower
across the sky in winter than in summer? This
is because Earth is tilted on its axis at a 23.5o
angle.
During winter part of Earth tilts away from the
sun. This causes the suns rays to strike that
part of Earth at a lower angle than in the
summer.
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Seasons- Remember its the TILT of the Earth
that causes the seasons
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Winter Solstice- shortest day of the year
Days are shorter nights are longer during
winter. This occurs in December in the Northern
Hemisphere in June in the Southern
Hemisphere. Each hemisphere receives less
sunlight therefore less heat energy during the
winter. This is why temperatures are colder
during winter.
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Summer Solstice- longest day of the year
This occurs in June in the Northern Hemisphere
and in December in the Southern
Hemisphere. Earths revolution around the sun
causes part of the Earth to tilt toward the sun
at different times of the year. This causes that
part of the Earth to receive more sunlight at a
more direct angle. This is why days are longer
and nights are shorter.
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Equinox
Equinox- means Equal Night Daytime lasts
exactly as long as nighttime on the first day of
autumn the Autumnal Equinox (about September
21) and the first day of spring - the Vernal
Equinox (about March 21).
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8 Planets
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The Sun Gravity
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The Sun is a Star
Our sun is a medium-size yellow star. In the
sun, hydrogen undergoes nuclear fusion, a process
that releases vast amounts of energy. During
fusion hydrogen atoms join to form helium atoms.
Hydrogen fusion is the source of light, heat, and
other radiation from the sun.
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Comets
Comets are made of various solids (like dirt
dust) and ice crystals. When their orbits take
them close to the sun, dust and ice heat up to
produce a tail behind the comet. Larger comets
may even become visible without the aid of a
telescope.
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Asteroids
Asteroids are rocky and usually follow regular
orbits around the sun. Asteroid belt- the
area between Mars and Jupiter that contains many
asteroids orbiting the sun.
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Nebulae
Nebulae are huge clouds of dust and gas. Some
scientists think that our solar system was formed
from nebula.
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Spiral
Irregular
Galaxies are groups of millions or billions of
stars. The galaxy we live in is the Milky Way
galaxy and has over 100 billion stars. It would
take 100,000 light years to travel across it!
Elliptical
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300,000,000 meters per second is the same as
300,000 kilometers per second. Thats the Speed
of Light!
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Light Speed!
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Closest star to Earth (besides the Sun)
Proxima Centauri is the nearest star to our Solar
System. Traveling at the speed of light, it
would take about 4 years 3 months to reach it
from Earth. (That makes it about 280,000 times
farther away from Earth than our sun!)
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H-R Diagram
In the Hertzsprung-Russell diagram each star is
represented by a dot. Stars are plotted by their
luminosity (brightness) and surface temperature.