It was 50 years ago that the giant radio telescope known by Australians as The Dish started operating in a sheep paddock in central western New South Wales.

Astronomers from around the world are in Parkes to celebrate the telescope's history and scientific discoveries.

Set among paddocks of yellow canola, golden wheat and sheep, the Parkes telescope is known for its role in helping broadcast one of modern history's biggest events: images of the first man landing on the moon.

The moments were further engrained in Australian culture by the locally made film, The Dish, which was made 11 years ago.

But CSIRO's chief astronomer Phil Diamond says the telescope's role goes far beyond NASA moon missions.

"Making the first map of the magnetic field in our own galaxy. Discovering more pulsars - these are the rotating remnants of supernova, exploding stars. Discovering more, in fact twice as many as all the other telescopes in the world combined," Mr Diamond said.

Space to play or pause, M to mute, left and right arrows to seek, up and down arrows for volume. Listen Duration: 4 minutes 14 seconds 4 m 14 s Bronwyn Herbert reports on The Dish's birthday Download 1.9 MB

"[It's a] huge range of science and it's still doing world-class science today."

Astronomers say the Parkes telescope keeps Australia at the forefront of radio astronomy and is capable of serving science for many decades to come.

Mr Diamond says the telescope is very much still "middle aged".

"The concrete and the metal are more or less the same as when it was built 50 years ago," he said.

"But it's the equipment that we put on it that makes it state of the art. And it has a very strong future, because it is still the largest radio astronomy telescope in the southern hemisphere."

Marcus Price, an emeritus professor at the University of New Mexico, is in Parkes this week for a scientific symposium celebrating 50 years of the radio telescope.

"I sometimes say immodestly that I think I know more about the telescope than anybody else alive, partly because I was here as they were finishing the building of it," he said.

"Plus the fact that when I became officer in charge, I of course went back and studied all the mechanical aspects of the telescope because it's our most important product to keep the telescope 100 per cent reliable so it was available for observers when they needed it."

Professor Price says he has many special memories from Parkes.

"The very first memorable moment I suppose was when they were doing testing on it initially and this involved doing the vibrational testing of the telescope to determine what its primary modes of vibration were," he said.

"And they would do this by running it up to full speed and then slamming on the brakes and it would make this rather noisy stop and rattle around a bit and I found that rather disconcerting ... I really thought the whole thing might just come down.

"Of course, after a while I learned that indeed it was quite substantial and nothing was going to happen. But the first couple of times that happened I really looked over my shoulder a bit, making sure I knew where the door was."

Professor Price says he cannot remember if cricket was ever played on The Dish, as happened in the movie.

"Although I have heard a rumour that one of the early graduate students and one of his colleagues did play a little baseball up there once," he said.

"I mean you don't lose the ball when you miss it. When it goes over your head it just rolls right back down to you."