Voyager Two, an interplanetary probe that was designed to observe and transmit information
back to Earth about our Solar systems largest planets.
Equipped with a payload of scientific instruments, the probe provided scientists with a wealth
of data, allowing us to explore the mysterious gas giants like never before.
Launched in August 1977, Voyager two and its twin Voyager one took advantage of a rare
planetary alignment that takes place every 176 years, providing the opportunity to fly
by Jupiter and then Saturn. Unlike its twin, Voyager twos designed trajectory,
meant that the probe was also able to continue to Uranus and Neptune. Becoming the first
and currently the only spacecraft to visit the solar systems outer planets, the ice giants.
Voyager two passed the mighty Jupiter in July 1979, nearly two years after it was launched
and captured incredible images of the gas giant and its many moons.
Then in August 1981, the probe arrived at Saturn, transmitting back many more spectacular
images of the planets magnificent rings, atmosphere and moons.
It would take another 4 and half years of travelling through the cold, dark expanse
of space however before we would get the first close up glimpse of the mysterious, Uranus.
In January 1986, Voyager two made its closest approach to Uranus, observing the mysterious
planets fascinating features, such as its moons, rings, atmosphere, internal structure
and magnetic environment. At this point, Voyager two was around 1.8
billion miles away from Earth, which is around 2.9 billion kilometres away and nearly 10
years into its historic mission. During the flyby, the resilient probe discovered
11 new moons, all of which were named after Shakespearean characters. Puck, Portia, Juliet,
Cressida, Rosalind, Belinda, Desdemona, Perdita, Cordelia, Ophelia and Bianca.
We were able to see spectacular close up photos of moons that we already knew existed in orbit
around Uranus, including Miranda, a moon with a jumbled up surface that appears as though
it was pushed together and broken apart several times.
Four other large moons were also closely photographed for the first time allowing us to observe
Oberon, Ariel, Umbriel and Titania, revealing their amazing geology.
As Voyager two completed its short flyby it studied the Uranian rings, nine of which were
already known to exist and two newly discovered by the spacecraft.
The rings turned out it be distinctly different from those found circling Jupiter or Saturn
and may be relatively young, likely not forming at the same time as Uranus. One theory is
that the particles that make up the rings may be the remnants of ancient moons that
collided and broke apart Observing the Uranian atmosphere, Voyager
two sent back photographs of a mostly featureless light blue planet, but it did record wind
speeds as high as 450 miles per hour, which 720 kilometres per hour and found evidence
of a deep, icy ocean. But this strange icy ocean isn't as we understand
it here on Earth, instead, it would be a highly pressurised, hot, dense fluid consisting of
water, ammonia and other substances. Data also revealed that the atmosphere is
similar to Jupiter and Saturn, being mainly composed of hydrogen and helium, but also
methane, making the planet a beautiful light blue.
Scientists had already discovered that Uranus was tilted on its side by 98 degrees before
Voyager two had arrived there, possibly as a result of an ancient catastrophic collision.
However the spacecraft did detect another bizarre feature on the ice Giant, it's mysterious
magnetosphere. The Uranian magnetic field is tilted by 59
degrees from the axis of rotation and does not pass straight through the centre of the
planet like many other planetary fields. This unusual arrangement creates an irregular field
and even today, scientists are unsure of what is causing this strange non-uniform phenomenon.
Voyager two came within 51,000 miles or 81,500 kilometres of the ice Giants cloud tops, allowing
the incredible probe to study the mysterious planet for around 5.5 hours during the historic
flyby. Then in February 1986, the spacecraft performed
a manoeuvre called a gravity assist that propelled it into the direction of the next and last
planet in the solar system, the magnificent, Neptune.
Like Uranus, Neptune had never been visited before and so Voyager two would become the
first-ever spacecraft to pass the distant blue planet. In August 1989, after a journey
that spanned 4.3 billion miles or 7 billion kilometres since it left Earth, the ambitious
probe arrived at its last planned destination. During the flyby, Voyager two found six new
moons that were later named Proteus, Larissa, Despina, Galatea, Thalassa and Naiad. But
it also photographed other already known moons, such as Neptune's largest, Triton.
Triton was revealed to be not only the most intriguing natural satellite in the Neptunian
system but one of the most interesting in all the solar system. These incredible images
present a bitterly cold moon with a remarkable geological history and even show an active
geyser-like eruption spewing invisible nitrogen gas out into space.
Tritons relatively high density and retrograde orbit also offer strong evidence that the
strange moon is not an original member of Neptune's family, instead, a captured object
from somewhere else. As Voyager two passed Neptune at just 3000
miles or 4,800 kilometres above the ice Giants cloud tops, the spacecraft detected a highly
active atmosphere, with wind speeds far exceeding 680 miles per hour, which 1,100 kilometres
an hour, the fastest detected during the entire journey.
Like the other gas giants, hydrogen and helium were found to be the most common element,
although the planets magnificent cobalt blue appearance is once again due to the presence
of methane. Originally it was thought that Neptune was
too cold to support atmospheric disturbances, however, Voyager two discovered large scale
storms, the largest was named the great dark spot.
This hurricane-like storm was about the size of Earth at the time and similar to Jupiters
Great Red Spot. But Neptune's massive storm didn't seem to last very long, at least by
giant planet standards, as just five years later the Hubble space telescope revealed
that the great dark spot had already dissipated. Voyager two also photographed four new rings
and revealed why Neptune's ring system is so faint, mainly because of the fine material
that its made up from. It confirmed that all of the solar systems gas giants have rings
and that known of them are as spectacular as Saturn's, although they are all fascinating
in their own way. After 12 years in deep space and successfully
exploring all four of our solar systems largest planets, Voyager two had finally completed
its initial mission. The amazing spacecraft studied different aspects
of the gas giants and allowed scientists to solve many of there mysteries. But the grand
tour of the outer planets had now come to an end.
Neptune was the last close encounter Voyager two will make for possibly millions of years,
but it will come relatively close to certain stars in the future as it silently drifts
through interstellar space, the place that is is currently exploring. After 43 years
in space Voyager two is still making discovers, etching its self into the history books as
one of the greatest and most resilient spacecraft ever to leave our planet. An achievement that
all of humanity can be proud of. If you would like to learn more about where
voyager two is predicted to be heading next then check out the video shown at the end
of this video. I hope you enjoyed hearing about Voyager twos incredible journey out
of the solar system, if you did then please hit the like button and subscribe for much
more to come. Thank you so much for watching and I'll see you next time.