Stars and Galaxies are Blocked from View

• One simple effect of star dust is that entire regions of space are blocked from view like the dark line running though the Milky Way or the Horse Head Nebula. Though most often very thin, the dust can clump together into "nebulae" that block light by deflecting light protons in all different directions. We know that there are stars behind the dust because some forms of energy like x-rays can cut through the dust to be picked up by specifically designed telescopes.
  
  

Star Forming Regions

• The earliest stars were composed of only those gases produced by the Big Bang but when they aged and went through the final stages of stellar evolution, heavier elements were produced. These were blown off as clouds of nebulae and sometimes in massive supernova explosions. These elements, formed in the stars through nuclear fusion, were then shot into the interstellar medium to become the building blocks of new stars. Gravity is the major force and once the dust fragments begin to collapse together, new structures are formed.
  
  

Supernova Explosions

• One of the final events of star evolution for some larger stars is a massive explosion that sends the entire mass of the star out into space in all directions. When such a supernova explodes it sends a shock wave of particles out into space that can disturb the existing nebulae, causing new currents and eddies. These currents, much like a whirlpool in water, concentrate the dust enough so that the particles become gravitationally attracted. If the attraction is strong enough more and more material will be added to the core until the pressure is enough to ignite nuclear fusion and a new star, often along with its planetary system, is born.
  
  

Interstellar Dust and Life

• Without the clumping of interstellar dust and the subsequent shocks that initiate stellar evolution, there could be no life on Earth. Most of the Earth is made of elements that are heavier than the original elements created in the Big Bang. These are only produced in normal stellar evolution and by supernova explosions. Explosions send out more dust to be spread throughout regions of space and when enough has clumped together, the process starts all over again.