Topic 8 Space

• What is our solar system?

  Planets, moons, asteroids, comets, and the sun.

  Our solar system consists 8 plantes:

  Mercury

  Venus

  Earth

  Mars

  Jupiter

  Saturn

  Uranus

  Neptune

  It can be remembered via the acronym: My Very Earthly Mother Just Served Us Nachos
• What is the life cycle of a star?

  Nebula (dust particles attracted by gravity) -> proto star -> Main sequence (pressure from fusion balanced within gravitational pull)

  A star can be similar size to our sun or bigger which affects its life cycle

  Similar: Red giant -> White dwarf (when fuel has run out) -> Black dwarf (once cooled)

  Bigger: Super red giant -> Supernova (when star is larger than our sun - produces heavy elements, and new nebula) -> Neuron star (very dense) or Black hole (so dense that gravity is so strong that not even light can escape)
• What are natural & artificial satellites?

  Natural: Moon

  Artificial: spacecraft

  They orbit the Earth.
• What type of orbit do satellites have?

  Circular; which means that while their speed is constant, their velocity is always changing, due to their direction changing.

  They're accelerating, but not getting faster
• What are artificial satellites used for?

  GPS, TV and communications
• What is meant by centripetal force?


  A force that always acts towards the centre of the orbit
• What is meant by an elliptical orbit?

  A satellite's orbit that gets fasters as it gets closer to Earth.

  Used for reconnaissance & weather
• What is red-shift?

  The shift of light towards longer wavelengths as it travels away from an observer, indicating that the object emitting the light is moving away.
• How does red-shift contribute to the Big Bang Theory?

  Red-shift suggests that all galaxies originated from the same position
• What do distant galaxies have?

  They are more red-shifted which means they're receding at a greater rate (moving away)
• How does CMBR contribute to the Big Bang Theory?

  Microwave radiation is detected from every direction of space which could be from the matter still cooling down from the Big Bang.