Choosing an Observatory Location

- Describe where infrared, ultra-violet and X-ray observatories are sited and explain the reasons why
- Demonstrate an understanding of the drawbacks to astronomers of the Earth's atmosphere and relate these to the need for optical and infrared observatories to be sited on high mountains or in space

Because of the many drawbacks of Earth's atmosphere, locations of observatories are carefully selected:

  • Frequently, larger observatories are built in remote locations far removed from light pollution.
  • They are also built on high mountains so there is less atmosphere to obscure viewing.
  • Also they are located in areas that have good, dry weather and fewer clouds, so typically nearer the tropics or Equator.
  • Dry weather is especially important for infrared astronomy as water vapour in the atmosphere is an interference.
  • Less infrared light penetrates to the surface so a higher location is better for those observations.


Other Observatories

  • X-Ray observatories are typically onboard spacecraft as are many ultraviolet and infrared observing stations.
  • Space telescopes also have the advantage of not having to deal with twinkling and turbulence in Earth's atmosphere.
  • Radio Telescopes are typically far away from cities and towns as microwaves from mobile phones and other transmitters interfere with signals



What are the factors that decide where an Observatory is to be built or positioned?