The discovery of the cosmic microwave background radiation (the echo of the Big Bang) led to the general acceptance of the Big Bang theory, certainly in the astronomical community. There were still opponents of the Big Bang, like Fred Hoyle who was the one who had coined the term "Big Bang" in the first place in order to ridicule the idea of an explosive "cosmic birth", but most astronomers by far were now convinced that the Big Bang had happened.
You can say that the discovery of the cosmic microwave background radiation did for the Big Bang theory what Hubble's discovery of Cepheid variables in the Andromeda galaxy did for the idea that there exist other galaxies.
Ann
