Space Physics

• What should you be able to describe by the end of the video on the solar system?


  The main parts of the solar system and how this is part of the Milky Way galaxy
• Why is the diagram of the solar system not to scale?

  Because the sizes of the sun and planets are very different and the distances involved are extremely large
• What is at the center of the solar system?

  The sun
• What type of celestial body is the sun?

  The sun is a star
• How many main planets are there in the solar system?

  Eight
• Name the four inner rocky planets of the solar system.

  Mercury, Venus, Earth, and Mars
• What are the four outer planets of the solar system classified as?

  Much larger gas giants
• What is an example of a dwarf planet mentioned in the material?

  Pluto
• What other objects are found in the solar system besides planets?

  Moons, asteroids, and comets
• What are moons classified as?

  Natural satellites that orbit planets
• How many moons do most planets in the solar system have?

  Most planets have at least one moon, and some have a large number
• What is the solar system a part of?

  The Milky Way galaxy
• What is a galaxy?

  A massive group of stars
• How many stars does the Milky Way galaxy contain?

  Hundreds of billions of stars
• How many galaxies are estimated to be in the universe?

  Hundreds of billions of galaxies
• What should you be able to describe by the end of the video on redshift?

  What's meant by redshift
• From what do stars such as the sun form?

  Clouds of dust and gas called nebulae
• How does redshift provide evidence for the Big Bang theory?

  It shows that galaxies are moving away from each other, indicating an expanding universe
• What is the main gas found in a nebula?

  Hydrogen
• What is the Milky Way galaxy?

  The galaxy that contains our solar system
• What happens to the cloud of dust and gas in the first stage of star formation?

  Gravity causes the cloud to collapse, increasing temperature
• How many galaxies does the universe contain?

  Hundreds of billions
• What is a protostar?

  A collapsing cloud of hot gas and dust
• What did astronomers observe about the light from distant galaxies in the 1900s?

  The light had an increased wavelength compared to light from closer galaxies
• What process occurs when the temperature of a protostar gets high enough?

  Hydrogen nuclei join together to form helium through nuclear fusion
• What happens when light from the Sun is passed through a prism?

  It produces a spectrum with dark lines due to absorption by specific elements
• What do the dark lines in the spectrum of sunlight represent?

  Wavelengths of light absorbed by specific elements in the Sun
• What is nuclear fusion?

  The process of hydrogen nuclei joining to form helium
• What is the lifecycle of a star described in the video?

  The lifecycle of a star includes stages from a nebula to a protostar, main sequence star, red giant, white dwarf, and potentially a black dwarf or supernova.
• What is redshift in the context of distant galaxies?

  It is the shift of spectral lines towards the red end of the spectrum, indicating galaxies are moving away
• What happens when nuclear fusion occurs in a star?

  It releases a huge amount of energy
• What does a larger redshift indicate about a galaxy's movement?

  The galaxy is moving away faster
• What are the two opposing forces acting within a star?

  The force of gravity acting inwards and the energy from nuclear fusion acting outwards
• What does the observation that distant galaxies are moving faster than nearby galaxies suggest?

  It provides evidence that the universe is expanding
• What does it mean when scientists say a star is in equilibrium?

  It means the force of gravity is balanced by the force due to fusion energy
• What do scientists believe about the origin of the universe?

  It began from a very small region that was extremely hot and dense
• What are the stages of star formation?

  1. Formation from a nebula (cloud of dust and gas)
  2. Collapse due to gravity, increasing temperature
  3. Formation of a protostar
  4. Nuclear fusion begins when temperature is high enough
  5. Star is formed and energy is released
• What is a nebula?

  A nebula is a cloud of dust and gas where stars begin their life.
• What will be covered in the next video?

  The life cycle of stars
• What is the Big Bang Theory?

  A theory that describes the universe expanding from a hot and dense state