Ames Area Amateur Astronomers (AAAA)
  Saturday, February 21, 2015
  Dark Matter and Dark Energy are huge mysteries in Astronomy.
  The observational evidence for both will be presented,
  including the observations and experiments under way to
  understand what Dark Matter is.

  Bio: Sam Wormley is a retired Associate Scientist and
  Principal Investigator at Iowa State and a retired Adjunct
  Prof of Astronomy at Marshalltown Community College. Sam
  regularly teaches science classes for the Osher Lifelong
  Learning Institute at Iowa State and for the RaySociety at
  Drake University.

  Astronomer's Tools
   - Spectral lines
   - Doppler shift

  Dark Matter
   - Galactic Rotation rates as measured by Doppler Shift of
     stars and gas

   - Motion of Galaxies in a cluster as measured by Doppler
     Shift of stars and gas

   - Gravitational Lensing (to determine mass of a cluster of

   - X-Ray imagery to determine the location and density of hot
     gas in galactic clusters

   - Dark Matter Candidates

  Dark Energy
   - Observation (Doppler and Brightness) of Type Ia supernovae
   - Observations of the CMB

  Summary -- the actual observation are of electromagnetic
  radiation, but as you can see above can be used to measure,
  motion within clusters and within galaxies, and gravitation
  effects to measure mass.