4. The launch of Sputnik I by the Soviet Union (1957)

The modern space era began with the launch of Sputnik I. The move into space, in retrospect, may prove to be the most significant development of the millennium. It led to many advances relevant to astronomy. These advances included the many interesting and valuable observations in the visible and ultraviolet parts of the spectrum from the Hubble Space Telescope during the 1990's.

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Jay M. Pasachoff is the Field Memorial Professor of Astronomy and Director of the Hopkins Observatory at Williams College. His Top 10 list largely relates major world events to a number of important developments in astronomy. He points to the establishment of the Nobel Prizes as an event that helped spark public interest in science.

1.

The development of radio astronomy (late 1900's)
2. The collapse of the Soviet Union (1991)
3. Dropping the atomic bomb in World War II (1945)
4.

The launch of Sputnik I by the Soviet Union (1957)
5. Introduction of the Nobel Prizes (1901)
6. Albert Einstein's theories of relativity (early 1900's)
7. Hitler's persecution of the Jews (1930's and 1940"s)
8. Discovery of the transistor and the rise of electronics (middle to late 1900's)
9. The development of computers (middle to late 1900's))
10. The invention of the airplane (1903)