Sir Patrick Moore died in December 2012 aged 89 after 55 years as the presenter of BBC television series The Sky at Night, having written more than 200 books, and composing a number of works of music including operas.
Visiting Sir Patrick's home in Selsey, West Sussex, for the unveiling, Brian May said: "Patrick was a friend to many of us and an inspiration to millions as it says on the plaque.
"It would be fair to say that a number of generations of astronomers owe their passion to, like me, begging their parents to allow them to stay up and watch Patrick while he was presenting The Sky at Night and of course he held the record in the whole world for the number of years presenting one program with one presenter."
Christopher Beaumont, Sir Patrick Moore's musical archivist, called the event 'superb' and said: "This place used to be very sad for a very long time but [the plaque] is all credit to the new owners. I think it's the right thing to do, it's superb."
Christopher's musical archive includes Sir Patrick Moore's famous xylophone and a number of his compositions, which Christopher aims to reproduce in the future.
John Morris, who helped to organise the unveiling, said: "He attracted an incredible number of followers, he just was incredibly enthusiastic about it, everyone who knew him loved him. Of all of Selsey's residents, Patrick is one of the most famous.
"It is because of his incredible contribution to the public understanding of science. He deserves to have a blue plaque."
John recalled going to Sir Patrick's home and helping him carry sacks of fan mail from his car, and said Sir Patrick would stay up until he had responded to every letter.