Imagination becoming reality

Comparing images from space with paintings of space.

The Cassini mission, a spacecraft launched by NASA and in orbit around Saturn for 13 years, recently ended.  The fuel to maneuver was running out, and it was decided not to leave it in place (where possible remaining microbes from Earth might eventually contaminate places that could have their own forms of life) but to send it to burn up in the atmosphere of the planet.  The decision also allowed closer looks at the inside of the rings and the planet itself than had been possible before.  It’s kind of sad, but the probe has left an amazing legacy.  Particularly striking are the pictures, some of which can be seen here.

To appreciate their impact on our older consultants, you have to realize that until late in the last century Saturn was a small, indistinct shape in even the best telescopes.  Yes, a few centuries of intense observation had made out the rings and some faint features on the planet itself.  But the Earth’s atmosphere, turbulent at the best of times, set a limit to the detail that could be detected.  And that limit hardly moved from the time of the first big telescopes, at the beginning of the nineteenth century, until the space age.  Photography helped, but even the fastest film had to be exposed long enough for the motion of the atmosphere to wipe out fine detail.  (The images at the beginning of this post show the very best that photography was able to do.)  The best veiws of the planet were gained by looking through the eyepiece, patiently waiting for a moment of steady air, then memorizing what one could see long enough to make a drawing.  The quality of an astronomer’s vision, memory and draftsmanship were crucial in this study long after photographs and instruments had taken over all others.

To fill in the details one had recourse to the imagination.  To be useful it had to be a disciplined imagination, one guided by what astronomy and physics could calculate or infer.  In the best hands it was both useful and spectacular.  Among the “best hands” we would place Chesley Bonestell, whose images we invite you to look at if you’re not familiar with them.

In particular, compare his paintings of Saturn with the pictures from Cassini.  Remember that, before space probes, we could only see the planet from nearly the direction of the Sun and not too far from the plane of the rings; there were no photographs showing a half-sunlit Saturn, or any looking down on the ring system from above.  Images like Bonestell’s were the only way to picture sights like these.

It’s no hyperbole to call the first space probes to the outer planets revolutionary.  Suddenly we had actual (electronic) photographs of scenes only imagined before.  Perhaps you had to live through it to appreciate the shock of something that had always been imaginary now being real.  And there was much more: the incredible thinness of Saturn’s rings, the fantastic whorls-within-whorls turbulence in the atmopheres of Jupiter and Saturn.

This is the pictorial counterpart of science fiction meeting reality.  How do you think it does?