Happy Carl Sagan Day!

Back in 1980 the US space programme was in the doldrums. Apollo was fading into history and there hadn't been a US astronaut in space for five years. The quirky space shuttle, much diminished from its initial vision, was still waiting to make its maiden flight.

But that fall came Cosmos, a revolutionary documentary series with a compelling host. Both the television universe and the real one have never been quite the same.

Carl Sagan, by equal measure professorial and childlike, offered space enthusiasts a new paradigm. Buck Rogers was out; refined and groovy cosmic citizen was in. Here was a visionary whose perspective dwarfed the politics of the space race and who spoke of humanity as a brotherhood with a common past and a transcendent future in the heavens.

"We are star stuff which has taken its destiny into its own hands," he told us. "The loom of time and space works the most astonishing transformations of matter."

Sagan, who died in 1996, would be turning 75th on 9 November, an occasion which has prompted Saturday's celebration of Carl Sagan Day.

Sagan's impact on science broadcasting is well known, and the Cosmos series lives on even though the celestial sights he rhapsodizes over have long since been surpassed by the Hubble telescope and planetary explorers like the Cassini mission.

But what of Sagan the author? Do his printed words still ring true at a time when the cosmic journey appears to be floundering on the rocky shoals of economic realism?

Remarkably, I think they do. Sagan had a knack for big ideas that spanned human history and entire domains of knowledge. He was king of the long view. As a planetary scientist he recognised the significance of being part of the first generation to reach out to other worlds. Yet his preoccupations were not so much the technical leap or even the scientific discoveries that accompanied the dawn of spaceflight, but the transformation in consciousness it represented.

Sagan's writings crossed from science to popular science gradually, starting with his academic ideas about intelligent life in the universe and his well-articulated skepticism about UFO's. Not until 1978 did his authorial voice truly come into its own, with the publication of a Pulitzer Prize-winning book, The Dragons of Eden, about the evolution of human intelligence.

Cosmos followed soon after, and then Contact, a novel about our first encounter with an alien intelligence. After that it was impossible to separate Sagan's written words from the sound of his mellow TV incantations-- a bit of a hindrance to the reader, but only a minor one.

I continue to recommend reading Pale Blue Dot, which at once captures the insignificance and the preciousness of our unlikely existence. It is here that Sagan so eloquently delineates the cold joy of science, which has taught us that, "because we have a talent for deceiving ourselves, subjectivity may not reign freely."

The theme is expanded in The Demon-Haunted World, a cautionary manual that arms readers against a rising onslaught of pseudoscience. What Sagan would make of the nonsense flying around the web today is anybody's guess. I imagine he would take the long view.

I once had the honour of introducing Sagan during a public lecture and I botched it hilariously. After rattling off his many achievements, I said that he was, above all "a curious fellow". What I meant was that he was the quintessential scientist. The audience heard it differently and much laughter ensued. Sagan laughed too and shook my hand with a forgiving grin before proceeding to blow the roof off the place.

His words managed to reach a lot of us in his 62 years. It's too bad he never got the role he was made to play: our first ambassador to another civilisation. I say this because Sagan seemed to hold all of us in his mind--our tragic past, our yearning for the sublime and our flickering hopes for something much bigger than we are today.

Happy 75th, Carl. Thanks a billion.