Solarsystem

• The universe is made up of billions of what?

  Galaxies
• Each galaxy contain hundred of millions of what?

  Stars
• Our solar system is tiny part of what galaxy?

  The Milky Way
• Our galaxy contains one star. What is it called?

  The Sun
• What do planets and dwarf planets in our solar system orbit?

  The Sun
• What do asteroids and comets in our solar system orbit?

  The Sun
• What do moons in our solar system orbit?

  Planets
• What are moons that orbit planets referred to as?

  Natural Satellites
• What was the sun formed by?

  A nebula that was pulled together by gravitational attraction
• What is a nebula?

  A cloud of dust and gas
• How did the sun change into a protostar after being formed from a nebula?

  As the dust and gas was drawn together, they collided , increasing the temperature and forming a protostar
• How did the sun change from a protostar into a main sequence star?

  As more and more material was drawn together by gravity , the number of collisions increased until the temperature and pressure was high enough for hydrogen nuclei to fuse together , forming helium and a main sequence star
• What keeps the core of the sun hot?

  The energy released by nuclear fusion
• What happened to material that was not drawn into the Sun during its formation?

  Material that was not drawn in remained in orbit around the new star and formed the planets and other objects in our solar system .
• True or False : The sun is still in the main sequence period of its lifecycle and is stable

  True
• The stability of the sun is the result of the balance of what 2 things?

  The fusion energy trying to expand the sun , and the gravity acting inwards, trying to collapse the sun