Sir Patrick Moore has presented the 650th episode of BBC One's astronomy programme The Sky at Night, nearly 50 years after the show first aired.
Sir Patrick presented the first show, when he was asked to do three programmes on astronomy in 1957.
At 83, he is British television's longest serving presenter, and still continues his own astronomy work.
But Sir Patrick is furious because the programme was given what he regarded as the poor time slot of 0155 GMT.
However the programme is normally shown in a late time slot.
The series began before the launch of the world's first man-made satellite, Sputnik 1, and the "space age".
But since then it has witnessed the first pictures of the far side of the Moon in 1959, the Apollo Moon landings of 1969 and the UK's total solar eclipse in 1999.
Many of the world's leading astronomers have appeared on the show, including Harlow Shapley, who first measured the size of the Milky Way galaxy, Carl Sagan and Fred Hoyle.
Astronauts Neil Armstrong and Buzz Aldrin have also been guests.
Without a big budget, the programme has often had to take innovative approaches to explaining our Solar System.
It has also had to deal with the problems of star gazing in a part of the world flooded with light.
Sir Patrick explained the show's enduring appeal: "Astronomy's a fascinating subject. You look up... you can't help getting interested and it's there. We've tried to bring it to the people.. it's not me, it's the appeal of the subject."