British astronomer and broadcaster Sir Patrick presented the BBC programme The Sky At Night for over 50 years, making him the longest-running host of the same television show ever.
He wrote dozens of books on astronomy and his research was used by the US and the Russians in their space programmes.
Described by one of his close friends as "fearlessly eccentric", Sir Patrick was notable for his habit of wearing a monocle on screen and his idiosyncratic style.
Sir Patrick presented the first edition of The Sky at Night on 24 April 1957. He last appeared in an episode broadcast on Monday.
A statement by his friends and staff said: "After a short spell in hospital last week, it was determined that no further treatment would benefit him, and it was his wish to spend his last days in his own home, Farthings, where he today passed on, in the company of close friends and carers and his cat Ptolemy.
"Over the past few years, Patrick, an inspiration to generations of astronomers, fought his way back from many serious spells of illness and continued to work and write at a great rate, but this time his body was too weak to overcome the infection which set in, a few weeks ago.
"He was able to perform on his world record-holding TV programme The Sky at Night right up until the most recent episode .
"His executors and close friends plan to fulfil his wishes for a quiet ceremony of interment, but a farewell event is planned for what would have been Patrick's 90th birthday in March 2013."
'Father figure' Patrick Alfred Caldwell-Moore was born at Pinner, Middlesex on 4 Mar 1923.
Heart problems meant he spent much of his childhood being educated at home and he became an avid reader. His mother gave him a copy of GF Chambers' book, The Story of the Solar System, and this sparked his lifelong passion for astronomy.
Sir Patrick Moore was the voice of the space age.
I recall as a child not following every detail of that famously rapid patter but I never minded - because like everyone who watched his broadcasts I was swept along by his extraordinary energy and excitement.
Here was someone who could catch the mood of a world enthralled by a heady mix of discovery and achievement.
With rockets launching satellites and then astronauts above Earth and beyond, there was no greater enthusiast to chronicle and illuminate an exhilarating new era of exploration.
Generations grew up with Patrick Moore as their guide and he proved hugely influential. Astronomy was no longer a niche activity ( via bbc.co.uk ).