Space Physics

• 1. Stars initially form from a cloud of dust and gas called a nebula.
• 2) Gravity pulls the dust and gas together forming a Protostar
• 3) Hydrogen begins to fuse to form helium nuclei and a star is born
• 4) The Star enters a main stable period of several billion years and is known as a Main Sequence Star
• 5) Eventually, the hydrogen begins to run out and the star swells into a red giant if it is small or a super red giant if it is large
• 6)A small star starts to become unstable and ejects its outer layer of dust and gas, leaving only the core behind- called a White Dwarf
• 7)As the White Dwarf cools down, it becomes a black dwarf.
• 8) Big Stars, however, start to glow more brightly again as helium starts to fuse and eventually they will explode into a supernova
• 9)Exploding Supernovas leave a very dense core called a neutron star once all the dust and gas has been ejected and if the star is big enough, it will become a black hole
• Stars and their life cycles produce and distribute all naturally occurring elements
• The Solar System is 8 planets, moons, dwarf planets and artificial satellites orbiting the Sun
• Gravity provides the force that creates orbits that are almost circular
• The size of the orbit depends on the object speed
• The Universe seems to be expanding
• Evidence for the expanding universe include longer wavelengths from distant galaxies and red-shift
• Red-Shift is the longer wavelengths of light are shifted to the red end of the spectrum
• Evidence suggests that the universe started with a Bang
• Dark Matter is the name given to unknown substances that hold galaxies together but does not emit any electromagnetic radiation