She started speaking quite slowly and even those in the audience aware of her role in life hardly imagined what was to come. Dr Carolyn Porco is only the fourth recipient of the American Humanist Association Isaac Azimov Science Award in the 20 years since its creation in 1988, and this was her acceptance speech.

She was brought up a Catholic and at first had sought answers in her religion. When these answers proved unsatisfactory she had sought answers in other religions. Finally she decided that the answers were not to be found in any religion, but could perhaps be found by looking outwards, beyond ourselves. She became an astronomer.

Carolyn Porco is head of the Cassini imaging team, responsible for bringing back to Earth and to the attention of the whole world the discoveries made by the Cassini spacecraft on its 11 year mission to Saturn. And what discoveries! Thanks to Cassini we have seen all of Saturn’s major moons, including the surface of its haze-enshrouded largest moon, Titan, 50 percent larger than our own Moon, and we’ve discovered previously unseen moons only a few miles across. But the rings, just 10 metres thick and hundreds of thousands of kilometres wide, stole the show at the Congress. The image of a total eclipse of the Sun by Saturn, displayed in high definition on the giant screen with the sun’s rays filtering through the rings, had many of us in tears. (See front cover). Zooming in, just visible through the outer ring on the left hand edge of the picture, was a tiny dot. “That is us, our planet Earth” said Carolyn, “from across a billion miles of interplanetary space”.

But there was more to come. One of the smaller moons, Enceladus, no bigger than Great Britain, is unlike most moons in the Solar System. Instead of being pock-marked by collisions with asteroids, comets and the like, it looks more like a snow field covered in ski tracks. Caroline revealed that in fact these cracks, fissures and mountain chains on the moon’s surface reveal a very geologically active body, due to the huge tidal forces churning and heating the moon’s interior. Some of these fissures – those straddling its south polar region -- eject plumes of vapour and fine icy particles into space.

But that isn’t all. The south polar region, and the fissures in particular, were found to be far warmer than the rest of the moon, and analysis of the plume material revealed the presence of water vapour and organic molecules.

We thus have, in one of the farthest reaches of the Solar System, the three main ingredients necessary to sustain life: heat, liquid water and organic material. If it should turn out that somewhere in its interior this small Saturnian moon does harbour life – even in its most primitive form – and it should turn out that life has arisen twice, independently, in our Solar System, then it will prove that life on Earth is not unique. Life elsewhere in the Universe would thus be a virtual certainty and overturn once and for all the religious view that life on Earth was God’s central creation. For this non-believer at least, it would demonstrate beyond all possible doubt that the man-created gods worshipped by most of our fellow humans reflect nothing more than a failure of human imagination. By finally removing humankind from any special role in the Universe, it would complete a process that began when Galileo first turned his telescope to the heavens.

Roy Brown is former President, IHEU.