The Voyager programme was first launched by NASA in 1977 to take advantage of a favourable alignment of Jupiter, Saturn, Uranus and Neptune. Although the original mission was to study only the planetary systems of Jupiter and Saturn, Voyager 2 continued on to Uranus and Neptune. Data and photographs collected by Voyager’s cameras, magnetometers and other instruments, revealed unknown details about each of the four giant planets and their moons.
Brian Cox revealed during his new BBC show “The Planets” the groundbreaking revelations.
Dr Cox said last month: “Almost nine years after leaving Earth, Voyager approached an entirely new class of planet.
“Just like Jupiter and Saturn, the planet’s upper atmosphere is composed mostly of swirling hydrogen and helium gas and hidden beneath lies an exotic, icy mix of methane, ammonia and water.
“But unlike the other gas giants, Uranus is almost featureless and for all the time that Voyager stared at the planet, it saw just 10 cloud formations.
“And we soon discovered why.”
Dr Cox went on to reveal how the probes also took a look at Uranus’ surrounding – revealing a truly astonishing fact.
He added: “Uranus, at -224C, is the coldest planet in the Solar System, the first of the ice giants.
“Voyager spent just six hours with Uranus and as its gaze widened it took in the entire system.
“And just like Saturn, Uranus has rings.
“But the rings are so dark, so faint that they’re very difficult to see from Earth.”
However, Dr Cox explained why these rings are still a great mystery to NASA.
He continued: “They must be made from some kind of material that doesn’t reflect a lot of sunlight back and we don’t know what that is.
“It can’t be water ice like the rings of Saturn, because they would be much brighter.
“They’re also extremely delicate and thin and again that’s a great mystery, you’d expect the particles to collide and spread over time – that doesn’t happen.”
It comes after Dr Cox also revealed one planet in the Solar System is “raining diamonds”.
Like Jupiter, Saturn is a massive ball made mostly of hydrogen and helium, but it contains much more sulphur than its fellow sister planet.
Dr Cox explained the significance: “Below the upper atmosphere great clouds of water grow and lightning 10,000 times more powerful than on Earth illuminates the sky.
“This lightning transforms the methane gas into huge clouds of soot.
“Deeper still, the pressure grows so great that these chunks of soot are likely transferred into diamonds.
“But even these diamonds will succumb to the pressure of Saturn, liquifying.”