Earth Science Chapter 19 – Earth, Moon and Sun

Astronomy – _____.

Rotation – _____

Axis – _____. (similar to axis on a car connecting two wheels)

Revolution – _____

Orbit – _____

The moon rotates and revolves

  • The moon revolves around us every _____
  • The moon also rotates at the same rate. Because of this the same side of the moon is always facing us.

Phases

  • The moon reflects light from the sun back to us. Half of it is always lit, but the phase of the moon depends on _____.
  • Full moon – _____
  • New moon – _____
  • ½ moon is actually a quarter. We see a quarter of the whole moon, half of what is lit up, half of a circle
  • waxing – _____
  • waning – _____
  • gibbous – _____
  • crescent – _____

Eclipses – when the moon’s shadow hits earth, or the earth’s shadow hits the moon

  • the moon orbits at an angle to our equator, it does not go directly around our center
  • Solar - _____
  • Lunar - _____. (only occurs when there is a full moon)
  • Umbra – _____
  • Penumbra – _____

Tides – the moon’s gravitational pull moves the water on the earth because the water is not permanently attached to one spot. This causes high and low tides.

Characteristics of the moon

  • Dry and airless
  • Small (diameter is less than the distance across the US)
  • Large variations of temperature (130 to -180 ºC)
  • 1/8th the mass of Earth
  • no liquid water but we are searching and are looking for it and have seen good signs

The moon formed when _____.

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Facts:

  • Earth completes 1 rotation every _____
  • Earth completes 1 revolution around the sun every _____ (0.25 days add up every 4 years to Leap Day in Feb.)
  • Earth’s orbit is slightly elliptical
  • Earth’s rotation is what causes the sun, moon, and stars to appear to move across the sky
  • Earth’s axis is tilted _____degrees

The seasons

  • Suns’ rays hit the earth more directly at the _____ than at the _____.
  • The poles do not receive as much energy as the equator because _____
  • This is why the poles are cold and the equator is hot
  • _____ of the earth causes the seasons.
  • When N hemisphere is tilted towards the sun (more direct rays) it is _____, when it is tilted away it is _____
  • S hemisphere is the _____
  • In the summer the sun is higher in the sky and the day is longer.
  • Solstice – _____ (actually at 23.5ºN or S latitude) 6/21 and 12/21 each year
  • Equinox – _____ (3/21 and 9/22) _____and the sun is _____.

What keeps the Earth and the moon in orbit instead of flying out into space? Gravity. Gravity is _____.

Law of Universal Gravitation – _____ (Sir Isaac Newton).

  • Strength of the force depends _____
  • Mass – _____
  • Weight – _____. Your mass does not change from planet to planet, but your weight does because each planet has a different gravity.
  • The smaller the mass, the _____ pull and object has
  • If distance increases between objects, the pull _____

Inertia – _____

  • This is why the earth does not fall into the sun
  • The earth has inertia from motion going away from the sun. This is what generates its orbit.

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Rockets

  • device that expels gas in one direction to move in the opposite direction
  • first ones made in China in 1100s
  • modern rockets first developed in the 1900s
  • orbital velocity – _____
  • escape velocity -_____
  • thrust – _____
  • amount of thrust depends on _____
  • more thrust = more speed

Multistage Rockets

  • smaller rockets are placed on top of each other and break off in stages as fuel is used up
  • 1960s Saturn V rocket was used to get to the moon

Race for space

  • 1957 Soviets launched _____
  • caused concern because we were in the Cold War and did not know what the Soviets could do with the satellite
  • 1958 US launched Explorer 1
  • 1958 US started NASA
  • 1961 Soviets launched _____ into space, orbited earth once
  • 1 month later American _____ was into space
  • 1962 _____orbited earth 3 times

Missions to the moon

  • _____ program – to get an American to orbit earth
  • _____ program – to look for landing sites on the moon and learn how to dock in space
  • Surveyor landed on the moon without people and didn’t sink in, proving we could land
  • _____ – land on the moon
  • 7/20/1969 – Apollo 11 Neil Armstrong and Buzz Aldrin entered the Eagle and landed in the Sea of Tranquility on the moon.

Today

  • space shuttles – can carry a crew into space, return to earth, land like an airplane, and be reused, rockets on the sides fall away once in space
  • _____– artificial satellite in which people can live and work for long periods, work began in 1980s and it still is being added to today
  • space probes – _____.
  • Rovers – _____.