PROGRESS IN ASTRONOMY

The 20th century has been a remarkable period for astronomers with no signs that they have stopped making fascinating new discoveries or that they have yet solve all of the universe many puzzles

Astronomers:

• Henry Norris Russel

showed that all the stars are going through a life cycle of birth, maturity and old age

• Harlow Shapley

used variable stars as yardstick to give the first good estimate of the enormous size of our own galaxy the "milky way"

• Edwin Powell Hubble

showed the some nebula's, faint and cloudy spots visible through telescope are actually extremely distant "island universe"