Looking into Space

Looking into Space

1. Radiation can tell us about stars and galaxies

   • The electromagnetic radiation a star emits ( -ray, radio waves etc..) tell us a lot (i.e the colour of the star gives us an indication of its surface temp)
   • Use parallax for distances to nearby stars
     • The greater the movement the closer the star
   • Brightness can be misleading as it could be close but very dim making it look further away than a bright star which is further away
     • Astronomers know how much radiation stars emit so by examining this they can tell how far it is

2. Atomosphere & Light Pollution cause problems

   • Atmosphere absorbs light coming from space before it reaches us
   • Light pollution makes it hard to see dim objects
   • To combat some of these problems scientists put telescopes in space

3. We see stars and galaxies as they were in the past

   • We see galaxies when the light left it so for an example we see the sun as it was 8 minutes ago as the light takes 8 minutes to reach us