<P> In 1922 , the Estonian astronomer Ernst Öpik gave a distance determination that supported the theory that the Andromeda Nebula is indeed a distant extra-galactic object . Using the new 100 inch Mt . Wilson telescope , Edwin Hubble was able to resolve the outer parts of some spiral nebulae as collections of individual stars and identified some Cepheid variables , thus allowing him to estimate the distance to the nebulae : they were far too distant to be part of the Milky Way . In 1936 Hubble produced a classification of galactic morphology that is used to this day . </P>
who is the first person to classified galaxies into groups according to their structure
Edwin Hubble