Science Worksheet

• Sun- The Sun is a star, a hot ball of glowing gases at the heart of our solar system.

  • Composed of about 70% hydrogen and 28% helium by mass.
  • The temperature on its surface is 5 500 degrees Celsius, and its core is 15 000 000 degrees Celsius.
• Sun-

  • Age: 4.6 Billion Years
  • Planets orbit the Sun in oval-shaped paths called ellipses.
• Earth-

  • Is the 3rd Planet from the Sun
  • Earths atmosphere:

  -78% nitrogen

  -21% oxygen

  -0.9% argon

  -0.1 % other gases.
• Earth- The atmosphere protects humans from other harmful materials coming from outer space.

  • Most of the surface is covered by water.
  • " blue planet"
  • Age: 4.5 Billion Years
• Rotation - is the spinning of the Earth on its axis.

  • Its axis is an imaginary line between the North and South Pole.
  • The axis is tilted at an angle of 23.5 degrees, pointing to the Polaris (North Star).
• Rotation- Because Earth rotates counterclockwise, it appears the Sun rises in the East and sets in the West.

  • 1 rotation = 24 hours (1 day)
• Rotation- The earth turns clockwise (west to east)
• Effects ot the Rotation of Earth-

  • Day and night- half of the Earth faces the Sun and has a day. The other half of Earth faces away from the Sun and has night.
  • Different Time zone
  • High tide and low tide
  • Wind speed and Direction
  • The apparent movement of all heavenly bodies from east to west.
• SUNDIAL – Oldest known in determining the time and most ancient of all the scientific instruments.
• Revolution-

  • is the movement of Earth in its orbit around the Sun.
  • 1 revolution = 365.24 days (1 year)
  • The speed of the Earth’s revolution is about 108 000 kilometers per hour.
• Effects of Revolution of Earth-

  • The change of seasons
  • The varying lengths of day and night
  • The changing altitude of the midday sun at different times of the year
• Seasons- are short periods of climatic change caused by the change in the amount of solar radiation an area receives.

  • The different seasons are caused by the tilting of Earth on its axis of rotation.
• Solstice- It comes from the Latin words sol meaning “sun” and stits “to come to a stop or stand still.”

  • It occurs 2 times a year when part of Earth is experiencing longer day or night
  • SUMMER SOLSTICE– LONGER DAYS
  • WINTER SOLSTICE– LONGER NIGHTS
• Equinox-

  • It comes from the Latin words aequus meaning “equal,” and nox– “night.”
  • It occurs two times a year when both the southern and northern hemispheres receive equal sunlight.
  • Spring or Vernal Equinox
  • Autumnal or Fall Equinox
• Spring or Vernal Equinox-

  • It marks the first day of spring and the beginning of a long period of sunlight.
  • It begins on March 20/21
  • When it is spring in the northern hemisphere, it will be autumn in the southern hemisphere, and the sun is directly over the equator.
• Summer stolstice- When the Northern hemisphere is tilted toward the Sun, this results in the Northern Hemisphere getting direct rays from the Sun.
• Summer stolstice-

  • Longer days shorter nights
  • Marks the beginning of summer on June 21/22
  • June 21 is the longest day.
  • Summer in the northern hemisphere and winter in the southern hemisphere.
• Autumnal or Fall Equinox-

  • It marks the first day of autumn and the beginning of a long period of darkness.
  • It begins on September 22/23.
• Winter stolstice-

  • When the Northern hemisphere is tilted toward the Sun, the opposite part which is the southern hemisphere is tilted away from the sun.
• Winter stolstice-

  • Sun appears to be low in the sky, and it experiences colder days or winter solstice.
  • Marks the beginning of winter on December 21/22
  • Longer nights, shorter days.