NASA / JPL

On August 25, 1981, NASA’s Voyager 2 spacecraft made its closest approach to Saturn. Although its twin Voyager 1 dropped by nine months before and the Pioneer 11 spacecraft had flown past it two years earlier, the Voyager 2 vessel rounded out our first close inspection of this intriguing planet.

Launched six days apart, the Voyager probes were critical for analysing how Saturn’s atmosphere changed with the seasons as they measured the wind speeds, temperature and density of Saturn’s atmosphere.

The spacecraft also revealed a great deal about the nature of Saturn’s moons – and identified four new ones – and confirmed the theory that the atmosphere of Saturn’s moon Titan was predominantly nitrogen.

Both Voyager vessels managed to give new insights into the mysterious rings that encircled the planet.

These findings were so impressive that they led to the discussion of a joint American and European mission to carry on the work just a year later. Those conversations eventually led to the Cassini mission which has been studying Saturn since 2004.

The ringed planet was just one of a few stops the probes made. Both took a look at Jupiter on the way to Saturn and afterwards, Voyager 2 travelled to Uranus and Neptune.

Both spacecraft are now in their extended mission to explore the far reaches of the solar system and beyond.

But some of the photos they took of Saturn and its moons are still breathtaking, even nearly 40 years on. Let’s take a look at a few.

NASA / JPL

One of the Voyager probes being assembled at the Vehicle (originally Vertical) Assembly Building at NASA’s Kennedy Space Centre.

NASA / JPL

An artist’s impression of a Voyager probe.

NASA / JPL

Saturn’s rings with “spoke” features in B-ring. This was taken by Voyager 2 on 22 August 1981, some four million kilometres away.

NASA / JPL

Colour variations in this enhanced image indicate different chemical compositions.

NASA / JPL

It looks a bit like the orange, brown and white palette of Jupiter’s wild weather, but Saturn has storms too.

This enhanced image of Saturn’s clouds was taken by Voyager 1 on 5 November 1980 at a range of eight million kilometres.

NASA / JPL

Saturn and three of its many moons: Tethys. Dione and Rhea.

NASA / JPL

Saturn’s sixth-largest moon, Enceladus – an icy world only 500 kilometres wide.

NASA / JPL

The massive canyon systems on Tethys may make it look as though it’s a rocky world, but it has the lowest density of any major moon in the solar system, indicating it’s made mostly of water ice.

NASA / JPL

Dione looks much like Earth’s moon – its cratered surface is lined with chasms and ridges.

NASA / JPL

Largest Saturnian moon Titan’s thick haze, snapped by Voyager 1 on 12 November 1980 from 435,000 kilometres.

There are still many Saturnian mysteries. These include what the exact length of a day on Saturn is, how old its rings are and whether or not the moons Titan and Enceladus might harbour life.