A grand adventure to unite us all

The world has watched this story for 20 years. Launched on October 15 1997 from Florida, the Cassini orbiter began its 3.4-billion kilometre trek to Saturn. It has been an extraordinary scientific achievement, uniting us all in its grand adventure.

The journey itself to the ringed planet took seven years on what Nasa described as a “gravity-assisted trajectory” — a few slingshots through space, if you will, performed through a glorious pirouette of mathematics and physics. It was Cassini’s long dance across the solar system, powered by two swing-bys of Venus, one of Earth and one of Jupiter.

Arriving at its destination, its mission proper began: orbit the ringed planet and study the Saturnian system in detail. In January 2005, the probe it had carried — Huygens — was parachuted to the surface of Saturn’s largest moon, Titan. Many of Titan’s secrets were revealed: rain, rivers, lakes and seas; a thick, nitrogen-rich atmosphere.

In the end, Cassini travelled 7.9-billion kilometres, completed 294 orbits of Saturn and carried out 162 close fly-bys of its moons. Through its many encounters with one in particular, Enceladus, the spacecraft discovered active, icy plumes spraying from “tiger-stripe” fractures. Titan and Enceladus are now considered the most promising places in our solar system to search for life.

Cassini’s grand discovery would also shape its own demise. Disintegration in Saturn’s atmosphere meant there was no chance any Earth microbes could contaminate either moon. But what a gift it gave, helping scientists from 27 countries gain a better understanding of the gas giant, its stunning rings and its icy moons.

Those confounding secrets give up their answers only as partial whispers. So we listen intently, exploring the unfathomable, endless abyss to bring a greater understanding of life and its creation. /Melbourne, September 17.