Astronomy: Day 2 Sun, moon and planets

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Astronomy Day 2Sun, moon and planets

• Wed., April 11
• Thurs., April 12

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Agenda

• Notes Moon, Earth, planets
• Activities moon phases, scale model of solar
  system

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Upcoming Dates

• WASL Late arrival for Tues-Friday 4/17-4/20

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Notes View from Earth

• A planet is any of the nine primary bodies that
  orbit the sun a similar body that orbits another
  star.
• Five planets (in addition to Earth) are visible
  to the unaided eye Mercury, Venus, Mars,
  Jupiter, and Saturn.
• The sun is our closest star.
• The solar system is the sun, planets, and other
  objects that orbit the sun..
• Everything revolves around the sun.
• The sun is the source of heat and light for the
  entire system.

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View from Earth

• Planets and distant stars are visible in the
  night sky.
• Earth is a part of a solar system.
• The sun makes up 99 of the total mass of the
  solar system.
• Gravity holds the solar system together.
• The force of gravity between two objects depends
  upon their masses and the distance between them.

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The View from Earth, continued

• Nine planets orbit the sun. (Now without Pluto -
  8 planets)
• A planets distance from the sun determines how
  long the planet takes to orbit the sun.
• Satellites orbit planets.
• ( examples of moons D\Ch19\80336.html)
• All of the planets in our solar system have moons
  except Mercury and Venus.

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Is Pluto still a planet?

• Article about Pluto
• http//www.msnbc.msn.com/id/14489259/

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The Moon

• The moon orbits Earth at a distance
• of 385 000 km.
• The maria, or large, dark patches on the moon,
  are
• seas of lava that flowed out of the moons
  interior,
• filled the impact craters, and cooled to
  solid rock.
• The moon has phases because it orbits Earth.
• A phase is the change in the illuminated
  area of one celestial body as seen from another
  celestial body
• phases of the moon are caused by the
  positions of
• Earth, the sun, and the moon.
• orbital path of moon D\Ch19\80317.html
• Formation of moon D\Ch19\80335.html

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Phases and Eclipses

• Phases of the moon are not caused by Earths
  shadow. Phases D\Ch19\80337.html
• Eclipses occur when Earth, the moon, and the sun
  line up. Eclipses D\Ch19\80338.html
• An eclipse is an event in which the shadow of one
  celestial body falls on another.
• The moon affects Earths tides.
• Coastal areas on Earth have two high tides and
  two low tides each day.
• Tides are mainly a result of the gravitational
  influence of the moon.

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Rotation vs. Revolution

• Rotation vs. revolution D\Ch19\80288.html
• Rotation vs revolution 2 D\Ch19\80288.html

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The Inner Planets

• The inner planets are called terrestrial planets.
• A terrestrial planet is one of the highly dense
  planets nearest to the sun Mercury, Venus,
  Earth, and Mars.
• Distances in the solar system are often measured
  in terms of the distance from Earth to the sun,
  which is one astronomical unit (AU), or 150
  million km.
• Mercury has extreme temperatures.
• Its day is 58 Earth days its year is 0.24 Earth
  years.
• It has almost no atmosphere and no water.

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The planets
Planet stats D\Ch19\80323.html
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Inner Planets
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The Outer Planets

• The planets most distant from the sun are
  Jupiter, Saturn, Uranus, Neptune, and Pluto.
• These large planets are called the gas giants.
• A gas giant is a planet that has a deep, massive
  atmosphere, such as Jupiter, Saturn, Uranus, or
  Neptune.
• Gas giants have no solid surface.

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Outer Planets
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Moon and Earths Tides

• The Moons gravity pulls on Earths oceans,
  creating high tide on the side facing the Moon.
• At the same time, the Moons gravity also pulls
  on Earth, so another high tide occurs on the
  opposite side.
• Tides are strongest when the Sun and Moon line up.

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Activities

• Phases of the moon
• Moon Tides Graphing Excercise