Physics : Term 2_Topic 2 - Space

Light travels at 300,000,000 m/s. A unit of length equal to the distance light travels in one minute. It takes 1.26 seconds for the light from the moon to reach the earth. Because distances in space can get very large, we can use the light year as a measure of distance. 1 light year is equal to 9.46 kilometers.

The moon is our only satellite It would take 2.52 seconds for light to travel from the moon to the earth A satellite is an object that orbits the earth. The light reflects when it hits the moon The speed of light is 300,000,000 m/s

If we didn't have so much light pollutions, we could see galaxies, galaxy clusters, shooting stars, stars, planets, meteors.

  • An asteroid is a rock that is too small to be a planet.

  • Rock, metal, and ice ranging in size from dist grains to small asteroids. These are called meteorites

  • The difference between a meteor and a meteorite is when a meteor is in the atmosphere and a meteorite is when it reaches the surface of the earth

  • Comets are cosmic snowballs of frozen gases, rock and dust that orbit the sun in large orbits. 

  • Galaxies are huge collections of gas, dust and billions of stars, and their solar system, all held together by gravity. 

  • To travel from one side of the milky way to the other, it would take 100,000 light years. 

  • Most galaxies look similar to discs. 

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  • Nebuli are just gas and dust. They are dead exploded stars    * The different colors in a nebula determine the gas. 

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  • Stars are spheres of gas held together by its own gravity. The star in our system is called the sun. the gases are mostly hydrogen and helium. 
  • The closer the planet, the faster it orbits the sun.
  • If mercury slows down, it will be absorbed into the sun by the gravitational pull in the sun. 
  • It takes 365 ¼ days to orbit the sun
  • The ¼ is added together for the 1 extra day every 4 years for a leap year, resulting in 366 days. 
  • It takes 23h 56m to rotate on its axis
  • The earth is 23.5 degrees tilted
  • Solar : to do with the sun

Nuclear fusion : Reaction takes place in the sun. hydrogen atoms fusing together to release light + heat energy.

Mini Quiz

  1. 23 hours and 56 Minutes 
  2. 365 ¼ days
  3. It produces light by the reaction of 2 hydrogen atoms fusing to create helium. Because of the Nuclear fusion (The chemical reaction taking place in the sun)
  4. The sun doesn't move, it is the earth moving on its axis which changes the perspective. 
  5.  True

The Earth's axis is the imaginary line through the centre of the Earth between the South and North poles. This axis is tilted slightly. We get different seasons because the Earth is tilted. When the northern hemisphere is tilted towards the sun it is summer  This means the southern hemisphere is tilted away and it is winter.

 \n Solar Eclipses : where the moon blocks the light from the sun. It can be partial eclipse where only part of the moon is covered. If iit is a total eclipse the entire moon is covered. The umbra is the direct shadow of the moon, a penumbra is a partial shadow of the moon. 

 \n A blood moon / lunar eclipse  is when the earth comes between the sun and the moon and turns the mood red. 

  • Lunar : to do with the moon
  • All other light is bent to earth, the red carries onto the moon
  • The red light bends the least amount as it is traveling from the sun to the earth, it is the only light that is portrayed on the earth and the moon will reflect red on earth. 

  1. A solar eclipse is when the moon comes and blocks the sun’s light while orbiting the earth. 

  2. A solar eclipse is when the moon comes in between of the sun and the moon, and a lunar eclipse is when the Earth comes in between of the sun and moon. 

  3. A lunar eclipse will occur at a full moon. This is because only the full moon will align with the sun and the earth. 

  4. The sun is bigger

  5. The two appear the same as the moon is because even though the moon is 400 times smaller than the sun, it is 400 time closer to the earth. 

  6. You would see the sides of the sun. Visually it would be the sun with a small hole through it. 

  7. The umbra section would be larger and the penumbra would be much smaller. 

5. The temperature would decrease and there wouldn’t be any sound from birds.

  • The moon reflects the light from the sun which explains why we can see it
  • It doesn't produce light it reflects it
  • It takes 29.5 days to orbit the earth
  • It makes it a natural satellite
  • It also spins on its own axis
  • The shape of the moon seen to change as it orbits the earth the different shapes are called the phases of the moon. Half of the moon is always lit by the sun but we cannot always see all of the lit parts.

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  1. The moon is ¼ th the size of the Earth
  2. We are able to see the moon because it reflects the light of the sun 
  3. Scientist have reached the moon and placed cameras and items to record and see how the earth looks from the moon 
  4. 29.5
  5. The closest to the sun as it can be

       1. A full moon is only visible at night as it is on the half non-lit side of the earth.

  1. A solar eclipse only happens during a new moon as that is the only time the moon is the closest to the sun.

Phases of the moon :

  • new moon
  • waxing crescent
  • first quarter
  • waxing gibbous
  • full moon
  • waning gibbous
  • third quater
  • waning cresent

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