One of the greatest marvels of space exploration is the Voyager 2!
Despite being active for more than four decades, the spunky spacecraft
is still going strong!
Even though billions of miles now separate the spacecraft
from us, it continues to amaze the scientific community with discoveries!
One of the most mind-boggling is the latest discovery and images that shock the entire
space industry!
What has the Voyager 2 discovered in deep space, what does the discovery
mean for the future of the space industry, and how do the discoveries affect
you personally?
What lies out there?
By out there, we mean the deepest part of space.
Are there aliens out there?
Or are civilizations making progress in technology as we are doing?
Are they trying to contact us as we are trying to contact
them?
The Voyager 2 spacecraft has had more than 40 years to find answers to these
questions, and what it has found out has been intriguing and enlightening, reminding us
that there is still a lot to be explored!
When preparing the two Voyagers for their mission, the engineers and scientists did
not imagine they could last this long, but as
it turns out, every day is a new record for the
two enduring spacecraft!
The Voyagers were actually built to last just five years and
conduct close-up studies of Jupiter and Saturn.
However, as the mission continued, Voyager 2 completed additional fly-bys of
the two outermost giant planets, Uranus and Neptune!
Voyager 2 is equipped with many scientific instruments to help it understand its
environment, including Imaging Science System (ISS), Ultraviolet Spectrometer (UVS),
Infrared Interferometer Spectrometer (IRIS), Planetary Radio Astronomy Experiment
(PRA), Photopolarimeter (PPS), Triaxial Fluxgate Magnetometer (MAG), Plasma
Spectrometer (PLS), Low-Energy Charged Particles Experiment (LECP), Plasma
Waves Experiment (PWS), Cosmic Ray Telescope (CRS), and Radio Science System
(RSS) What exactly has allowed the Voyager 2 to
remain active for so long?
Well, the spacecraft left with a power source that lasts
very long, which is why it can still send and
receive signals from the control station and take readings of its environment.
It is not powered by solar because the Sun does not
reach the part of space the Voyager is in right now.
Instead, it relies on radioisotope thermoelectric generators, RTG, for their
energy, the main reason they can still work.
The spacecraft has three RTGs using plutonium 238 as fuel.
The isotope decays, it generating heat which is converted to electrical
energy.
Voyager 2 took off with the capacity to generate 470 watts at 30 volts
DC, but that capacity has waned over the years.
As the fuel depletes, so also do the thermocouples used in the system degrade
over time!
The project managers said that as of 2011, Voyager 2 was producing just
under 270 watts or about 76 percent of the power they started out with.
But that is still enough for the spacecraft to at least get
by!
Another reason the Voyager 2 is still working is that it has been receiving updates!
As it flew across the solar system, managers used
remote-control reprogramming to give Voyager 2 greater capabilities than what it
possessed when it left Earth, which allowed them to change its itinerary as necessary.
Also, the signal receiving equipment back on Earth has also been upgraded to make
sure they can handle the large distance.
Where is Voyager 2 right now?
Of course, its position keeps changing as it hurtles
through space at high speed, but it has left the heliosphere, the same as its twin.
But that does not mean the Voyager 2 has left
the solar system!
In fact, it might never leave it.
The solar system's boundary is considered to be beyond the outer edge of the Oort
Cloud, a collection of small objects that are still under the influence of the Sun's
gravity.
The width of the Oort Cloud is not known precisely, but astronomers think it begins at
about 1,000 astronomical units or AUs from the Sun and extends to about 100,000 AU!
1 AU is the distance from the Sun to Earth.
At the speed it is moving, it will take Voyager 2 about 300 years to reach the inner
edge of the Oort Cloud and possibly 30,000 years to fly beyond it!
If the lifetime of Voyager 2 is divided into chapters, chapter 1 would be Jupiter, which
it approached two years after launch.
It explored the gas giant, its magnetosphere and
studied its moons in greater detail than Pioneer had explored.
Voyager 2 sent us awe- inspiring photos of the entire Jovian system,
and the time-lapse movies made from its images of Jupiter showed how the planet had
changed since Voyager 1's visit.
The spacecraft also studied the Great Red Spot, the largest storm in the solar system.
It also discovered the 14th moon of Jupiter known
to us.
Chapter 2 is Saturn, which Voyager 2 arrived at in 1982.
Thanks to its photooparimeter, Voyager 2 observed the planet's rings at a
much higher resolution which led to the discovery of many more ringlets.
It also provided more detailed images of the ring
spokes and kinks, the F-ring, and its shepherding moons.
The next chapter opened after the spacecraft used a gravity-assist maneuver at Saturn
to help it reach its next port of call, Uranus.
It was the first-ever and only spacecraft to
visit Uranus in 1986, where it found evidence of an ocean of boiling water about 500
miles or 800 kilometers below its cloud tops.
It also turned up ten new moons, a new pair of rings, and a strangely tilted magnetic
field stronger than Saturn on Uranus.
The spacecraft also witnessed that the planet
is tilted by 98 degrees, which means it essentially spins on its side!
Chapter five is the fly-by of Neptune, which has received no visit from another artificial
object.
It flew about 3,100 miles or 5,000 km above the planet, where it discovered five
moons and the Great Dark Spot, which no longer exists.
Voyager 2 also confirmed that Triton, the largest moon attached to Neptune,
was the coldest planetary body in the solar system!
In Aug. 2007, Voyager 2 opened another chapter when it passed the termination shock
and then entered the heliosheath.
By November 2017, the spacecraft was 116.167 AU
or about 10.8 billion miles or about 17.378 billion kilometers from Earth.
It was moving at a velocity of 9.6 miles per second or15.4
kilometers per second relative to the Sun, heading in the direction of the constellation
Telescopium.
Voyager 2 exited the heliosphere in 2018, following in the footstep of Voyager 1 six
years earlier.
The heliosphere is the protective bubble of particles, radiation, and
magnetic fields created by the Sun.
What did the spacecraft see at this point?
Some of the discoveries were similar to what Voyager 1 saw, even though they are
headed in different directions.
Voyager 2 measured a jump in the density of particles
accompanied by a sharp decrease in their speed and a shift in the magnetic fields.
However, there are some differences that gave clues about the complicated dynamics
in that region of the solar system.
The Sun spews in all directions a continuous stream of particles called the solar wind.
It travels at an unimaginable speed of a million
miles per hour.
The particles are mostly hydrogen, but when heated to about 3 million
degrees Fahrenheit, the atoms are ripped apart into protons and electrons.
At a distance of more than 11 billion miles from the Sun, the solar wind, thinning out,
is increasingly buffeted by the flow of particles
in the interstellar wind and a galactic magnetic field generated by the long-ago explosions
of distant stars.
The interstellar wind is much cooler and denser.
As it approached the boundary, Voyager 1 noted the outward velocity of the solar wind
dropped to zero long before actually reaching the boundary because it was pushed
sideways.
However, for Voyager 2, the outward velocities fluctuated, sometimes dipping
to zero but then rising again.
Scientists were not expecting so much difference in the heliosphere crossing
experiences of the two spacecraft because they were crossing at roughly the same
distance away from the Sun.
This discovery forced scientists to reexamine their models.
Voyager 2 also measured what scientists describe as a magnetic barrier.
This is like the pile-up of slowly moving cars on a major highway,
a few miles ahead of the scene of an accident.
When the solar wind slows, the density of particles increases, and the
magnetic field strengthens.
What happens when the power source on the Voyager 2 finishes?
Sadly, we will get to that point one day.
Even before that day comes, scientists have been shutting off some
features on the two Voyagers to save on energy.
However, scientists are already planning a replacement mission.
Using all they have learned from the Voyagers, the new spacecraft
will travel way faster than the Voyagers, allowing it to arrive at the heliosphere way
faster.
Such a probe would first head to Jupiter, using the giant planet's gravity
to accelerate toward the Sun.
As it then swings around the Sun, the spacecraft would fire
a rocket engine, accelerating to a speed that could cover close to a couple of billion miles
a year.
That would be more than five times the speed of the Voyagers!
Let's hear what you think of Voyager 2 in the comment section below