Tributes poured in immediately for eccentric stargazer Sir Patrick Moore as news of his death broke.
Queen guitarist Brian May, who holds a PhD in astrophysics, led the chorus of praise, saying the world had "lost a priceless treasure that can never be replaced" and he had lost a "dear friend and kind of father figure".
May said in a statement: "Patrick was the last of a lost generation, a true gentleman, the most generous in nature that I ever knew, and an inspiration to thousands in his personal life, and to millions through his 50 years of unique broadcasting.
"It's no exaggeration to say that Patrick, in his tireless and ebullient communication of the magic of astronomy, inspired every British astronomer, amateur and professional, for half a century.
"Patrick will be mourned by the many to whom he was a caring uncle, and by all who loved the delightful wit and clarity of his writings, or enjoyed his fearlessly eccentric persona in public life," he added.
"Patrick is irreplaceable. There will never be another Patrick Moore. But we were lucky enough to get one."
Professor Brian Cox, who presents a number of science programmes for the BBC, tweeted: "Very sad news about Sir Patrick. Helped inspire my love of astronomy. I will miss him!"
Former BBC science correspondent and fellow astronomer Dr David Whitehouse told Sky News that Sir Patrick had "loved astronomy more than he loved himself".
"He was passionate, he was dedicated and had an unselfish love of astronomy and he passed that on to everybody who knew him and he came across.
"He was a difficult person personally to deal with on many occasions, he was sometimes awkward, truculent, stubborn but that was Patrick, that was part of his remarkable personality which so many people came to enjoy and love.
"I think many people realised he was a unique person.
"He was not a professionally trained astronomer and yet did professional quality work, particularly when it came to mapping the Moon in the 1950s - I think every astronomer in the world owes something to Patrick Moore."