How far have we as a species travelled into the depths of space?
Take a look at this real picture. That tiny pale blue dot? That s us. That, is Earth.
On August 25th 2012, Voyager 1 left the solar system, making it the first man-made object to
do so. Whilst on its journey towards interstellar space, it captured this record-breaking image,
picturing Earth from 6 billion kilometres away, or roughly 40 times the distance between Earth
and the Sun. And this was back in 1990. Voyager 1 hasn t stopped travelling further into the expanse
of space since. So what else did the Voyager missions find along the way? Stay tuned to find
out about Voyager s important discoveries backed up with more real images, here, on Elderfox.
Amidst the height of the space race between the world s then two superpowers, the United
States and the Soviet Union, the idea for the Voyager programme was put forward to the NASA
Jet Propulsion Lab. American aerospace engineer Gary Flandro discovered that there would be a
rare alignment of the solar system s outermost gas giants in the late 1970s, allowing passing
spacecraft to perform gravitational assists. This would drastically reduce the time needed to travel
out of the solar system, creating an opportunity which NASA could simply not pass up. Under normal
circumstances, it would take 30 years for a space probe to reach Neptune, the furthest planet from
the sun. However, by using the gravitational assists available to the Voyager missions,
Neptune could be reached in just 12 short years. This alignment occurs only once every 175 years,
meaning that time was of the essence for NASA to develop and launch the Voyager probes
on their grand tour of the solar system. On August 20th 1977, Voyager 2 was launched into
space, 16 days before its sister craft Voyager 1. However, Voyager 1 would eventually pass
Voyager 2 on its way out of the solar system, as it was on a different, faster trajectory.
During the course of their main mission, the probes would visit Jupiter and Saturn, although
Uranus and Neptune were added as destinations for Voyager 2 after its launch. The probes were
primarily designed to beam collected data back to Earth, all the while capturing breath-taking
images of their planetary pit stops. NASA scientists were also wary about the
potential for extra-terrestrial life to one day find and intercept either of the Voyager craft,
as the probes would be travelling further into the expanse of space than anything before them.
American astronomer Carl Sagan assembled what have since become known as the Voyager Golden Records.
These records contain basic information about life here, back on Earth, and were mounted aboard each
Voyager probe to act as a sort of greeting to any intelligent life which may stumble upon it.
First up on Voyager s grand tour of the solar system was Jupiter. Most importantly, the moons
of Jupiter, which were observed in all their glory. Callisto, Europa and Ganymede were all
photographed up close, but astoundingly, Voyager 1 was able to capture this first close look at
IO. Here, a volcano on IO can be seen erupting, blasting tons of matter into the vastness of
space. Scientists had their suspicions of volcanic activity on the moon due to the reddish colour of
the surface, however more images showed at least 8 volcanoes erupting, confirming IO as the most
active volcanic body in the solar system. The close flyby of Jupiter also allowed the
Voyager probes to snap images of the planet s never before seen rings,
which are so faint that only the largest of today s modern telescopes can see them.
The next stop on Voyager s tour was Saturn. Three new moons were discovered: Atlas,
Pandora and Prometheus, however the moon Titan was of the greatest interest to scientists.
Titan is the only moon with a thick atmosphere in the solar system,
and due to data captured by Voyager concerning Titan s thick haze, liquid lakes of hydrocarbons
were speculated to exist on its surface. This was later confirmed by the Cassini spacecraft.
Enceladus was also discovered to be the most reflective body in the solar system during
Voyager 2 s mission, a result of it being completely covered in fresh, clean ice.
Regarding Saturn itself, winds of over 1,100 miles per hour were measured by
Voyager 1 close to Saturn s equator, and auroras were spotted near each pole.
At this point, Voyager 1 continued its way to the outer reaches of the solar system,
whilst the Voyager 2 mission was extended so that the probe would fly past Uranus and Neptune.
Voyager 2 reached Uranus in 1986, almost 9 years after its launch. Gathered data revealed 11 new
moons and 2 new planetary rings. The surface temperature of Uranus was recorded at a frosty
-213 degrees Celsius, and surprisingly, both of its poles exhibited nearly the same temperature,
despite only one of them receiving daylight. Following a mid-course correction in 1987,
Voyager 2 reached Neptune in 1989. Previously unknown Neptunian rings were discovered,
along with 6 new moons. The surface of Neptune was extensively pictured, revealing clouds and
the so called Great Dark Spot. This phenomenon is theorised to be the result of a large pocket of
clear gas, which provides a window through Neptune s cloudy skies. However, the Great Dark Spot has
since disappeared, according to observations made by the Hubble Space Telescope.
After passing Neptune s largest moon Triton, the coldest of any natural body in the solar system,
Voyager 2 continued its mission towards interstellar space.
Since the reclassification of Pluto as a dwarf planet in 2006,
Voyager 2 s visit to Neptune in 1989 retroactively became the point when
every known planet in the solar system had been visited by a man made spacecraft.
So now that the Voyager missions have achieved their original
objectives, where will they go next? Pluto was considered as a viable option
for both probes to visit. However, Voyager 1 s trajectory was off due to the prioritisation of
its flyby of Saturn s moon Titan, whilst Voyager 2 didn t get the go ahead due to cost overruns.
Instead, both probes crossed beyond the heliosphere and into
interstellar space. Voyager 1 doing so in 2012, whilst Voyager 2 followed in 2018.
The Sun protects our solar system by ejecting plasma and creating solar wind. This in turn
creates a bubble around our solar system known as the heliosphere, which keeps out
dangerous amounts of radiation and cosmic rays coming towards us from interstellar space.
Not much is known about this area in space, which is why the Voyager missions
are collecting vital data from there. Today, both probes are still moving through
this precarious region of space, although due to dwindling electrical power, both Voyager 1
and 2 are expected to hang up their cosmic exploration boots at some point between 2025
and 2030. A well-deserved end to their colossal celestial journey.
Although the Voyager probes never got to see Pluto, a more recent probe did! The New Horizons
probe found skyscraper-like structures made of methane ice as well as other bizarre phenomenon.
Click here to see what else it found on Pluto. Thanks for watching Elderfox. Remember to
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