Transcript of a message to Nasa when the Cassini spacecraft flew close by Iapetus. Iapetus was the original setting for the monolith in Clarke's book.
I'm delighted to be part of this event to mark Cassini's flyby of Iapetus.
I send my greetings to all my friends - known and unknown - who are gathered for this important occasion.
I only wish I could be with you, but I'm now completely wheelchaired by Polio and have no plans to leave Sri Lanka again.
Thanks to the World Wide Web, I have been following the progress of Cassini-Huygens mission from the time it was launched several years ago. As you know, I have more than a passing interest in Saturn.
And I was really spooked in early 2005, when the Huygens probe returned sound recordings from the surface of Titan. This is exactly what I had described in my 1975 novel Imperial Earth, where my character is listening to the winds blowing over the desert plains.
Perhaps that was a foretaste of things to come! On September 10, if everything goes according to plan, Cassini would give us our closest look at Iapetus - one of Saturn's most interesting moons.
Half of Iapetus appears as dark as asphalt, and the other half is as bright as snow. When Giovanni Cassini discovered Iapetus in 1671, he could only see the bright side. We had a better glimpse when Voyager 2 flew past in August 1981 - but that was from almost a million kilometers away.
This is a particularly exciting moment for fans of 2001: A Space Odyssey - because that's where the lone astronaut Dave Bowman discovers the Saturn monolith, which turns out to be a gateway to the stars.
Chapter 35 in the novel is titled 'The Eye of Iapetus', and it contains this passage:
"Iapetus was approaching so slowly that it scarcely seemed to move, and it was impossible to tell the exact moment when it made the subtle change from an astronomical body to a landscape, only fifty miles below. The faithful verniers gave their last spurts of thrust, then closed down forever. The ship was in its final orbit, completing a revolution every three hours at a mere eight hundred miles an hour - all the speed that was necessary in this feeble gravitation field."
More than 40 years later, I cannot remember why I placed the Saturn monolith on Iapetus. At that time, in the early days of the Space Age, earth-based telescopes couldn't show any details of this celestial body. But I have always had a strange fascination for Saturn and its family of Moons. By the way, that 'family' has been growing at a very impressive rate. When Cassini was launched, we knew of only 18 moons. I understand it is now 60 - and counting.I can't resist the temptation to say:
My God, it's full of moons!
But in the movie, Stanley Kubrick decided to place all the actions at Jupiter, not Saturn. Why this change? Well, for one thing it made a more straightforward storyline. And more important, the special effects department couldn't produce a Saturn that Stanley found convincing.
That was just as well because if they had done so, the movie would have been badly dated by the Voyager missions, which showed Saturn's rings to be far more implausible than anyone had ever imagined.
I have seen enough instances where Nature imitates art, so I'm going to keep my fingers crossed on what Cassini discovers at Iapetus.
I want to thank everyone associated with this mission and the overall project. It may lack the glamour of manned spaceflight, but science projects are tremendously important for our understanding of the Solar System. And who knows, one day our survival on Earth might depend on what we discover out there.
This is Arthur Clarke, wishing you a successful flyby.