The approximate radius of the solar system is 30 trillion kilometers.
During the whole time of exploration of this space, mankind has found 316 minor planets.
And 8 main ones that everyone knows about.
But “know” is too big a word.
In most cases, we only know what these planets look like and at what distance they are from
the Earth.
Everything else is just our assumptions.
To replace speculation with facts, humanity regularly sends space research probes to other
planets.
One of the most significant and truly epochal missions was "Cassini-Huygens", the purpose
of which was to study Saturn and its satellites.
Namely - the search for answers to the questions: "What threat are the rings of Saturn?"
"What does the surface of the planet actually look like?" and, most interestingly, “Is
life possible there?”
October 15, 1997.
Cassini was launched into space by NASA.
A high-tech object the size of a school bus and worth $3 billion.
In order to accelerate such a device, it was necessary to use the gravitational field of
three planets.
It passed next to Venus twice - in 1998 and 1999.
Then, at a speed of 69 thousand km/h, it rushed near the Earth.
And only a year later, in 2000, it picked up the required speed, passing by Jupiter.
It was not so easy to accelerate the device weighing 5710 kg - but with each new month
it became easier.
After all, more than half of Cassini's weight was fuel, the reserves of which were decreasing
every day.
Having flown three and a half billion kilometers, "Cassini" approached the rings of Saturn.
In photographs, they appear smooth and gaseous.
But in reality, these are billions of space debris pieces ranging in size from a fingernail
to a huge building.
And given the speed at which the Cassini was moving, a collision with even the smallest
fragment was enough for the entire apparatus to be instantly destroyed.
But luckily, Cassini made it through the rings safely.
And it sent unique footage to Earth, which helped make several amazing discoveries.
For example, scientists used to think that each of the rings of Saturn is the same.
But Cassini's pictures showed that all the rings are different - even those that are
close to each other.
In addition, scientists were able to find out that the thicker the rings - the older
they are.
Thanks to gravitational measurements during the maneuvers, Cassini found that the approximate
weight of Saturn's rings is 15 400 000 000 000 000 tons.
Most likely, Saturn's gravity is tearing apart icy moons and comets.
From their debris, the rings are formed.
But in 2004, Cassini photographed something else that especially interested scientists.
In one of the outer rings of Saturn, they documented the presence of small moons.
Scientists have taken pictures of the particles they are composed of, collecting and scattering
nearby small satellites.
In other words, Cassini managed to photograph the moment of the formation of a smaller system
within a system!
This is an absolutely grandiose find.
According to scientists, thanks to the observation of these processes, it is possible to obtain
information about the formation of our solar system – in the end, we will be able to
find out how planets are formed in protoplanetary disks.
And one more shocking discovery: Saturn devours its own rings!
From the rings to the surface of Saturn, there is a real shower of water droplets and dust.
And “shower” is saying too little.
This is a real cosmic hurricane, because every second Saturn devours up to 45 tons of ring
matter.
During its mission, Cassini documented the dynamics of the change of rings - rings D
and C are going to disappear.
But by human standards, Saturn will not devour its rings soon - for this it will take at
least 700 thousand years.
But the main goal of Cassini, of course, is not the rings - but Saturn itself and its
satellites.
And the resulting photos of the planet did not disappoint.
Cassini managed to record an incredible storm at the planet's North Pole.
Its diameter is 32 thousand kilometers, and its speed is 150 m/s.
It's scary to even imagine how it looks from inside.
And what is phenomenally different about it - this storm has a perfect hexagonal shape.
This storm is 50 times the size of a hurricane on Earth.
And the even walls of this vortex go deep into the atmosphere at up to 100 kilometers!
Research into the origin of this storm is still ongoing.
In total, Saturn has 82 known satellites with a confirmed orbit, each of which is somehow
different.
For example, Hyperion is a natural satellite, looking like a 360-kilometer potato.
The pictures showed that it was all composed of rocks and ice.
Hyperion looks like it survived a terrible bombardment.
But the porous surface is not explained by this, but by the extremely low density of
the planet.
Because of this, only 60% of the planet is composed of ice, rock and metal impurities.
And the rest of its internal volume is made up of cavities, which we also see in Cassini's
photographs.
Another satellite of Saturn, Tethys, raises a lot more questions.
Cassini took color photographs, which clearly show unidentified red stripes on the surface
of the satellite.
Their origin is a mystery.
They look as if someone drew them.
One of the versions is the huge cracks that formed on the satellite.
As if something is splitting Taphia from the inside.
But what is it - hot lava or unique chemical components?
So far, it has not been possible to find out.
But the most interesting is the most important satellite of Saturn - Titan.
To investigate Titan, a specially designed Huygens probe was placed in Cassini.
On December 25, 2004, Cassini launched Huygens into the hazy atmosphere of Titan.
The probe entered the atmospheric layers of the satellite.
Due to the terrible friction, Huygens' heat shield warmed up to 1,500 thousand degrees.
But the probe survived and landed safely.
Before Cassini's trip, no one could even imagine what surface the probe would land on.
But all signs of landing indicated that Titan's surface is a hard surface, beneath which is
a soft and light substance.
Further discoveries were truly amazing.
It turned out that Titan is the best factory known to man for the production of organic
compounds.
Almost the entire satellite is covered with a layer of frozen hydrocarbons that resemble
gasoline.
In other words, if humanity dug a mine on Titan, then we would be able to provide the
entire Earth with oil for thousands of years.
But that's not all.
The most important discovery was ahead.
Judging by all the data obtained by Huygens, Titan's atmosphere is predominantly nitrogen.
Just like the atmosphere of our planet!
That, together with complex carbon compounds in Titan's foggy atmosphere, allows to suggest
that Titan is a suitable place for the existence of life.
One minus - it's too cold on it.
That, however, does not interfere with the existence of deep lakes, thousands of years
old.
True, if on Earth reservoirs are filled with fresh or salt water, then on Titan they consist
of methane and ethane with a temperature of about minus 180 degrees Celsius.
You will hardly want to swim in there on vacation with your family.
Huygens' expedition made it clear that Titan is the most Earth-like object in the Solar
System known to us.
There are also lakes here, seas, flowing rivers, rain falls.
There is even a change of seasons here.
True, each of them lasts for 7 Earth years.
The potential for exploring this planet is very high.
And in the future, if humanity does begin to colonize, Titan will most likely be used
as a galactic station for the extraction of resources.
However, the discoveries on Titan are not the most astounding ones that Cassini made.
By pure coincidence, scientists came across other information.
Saturn's other moon appears to have life!
It's about Enceladus.
It is covered in ice, but it shines like a lamp.
Its surface reflects more light than any other body in the Solar System.
When Cassini approached the satellite, it made interesting shots against the background
of the Sun.
They showed that Enceladus has its own geysers that eject water vapor and ice into space.
The temperature at the South Pole turned out to be much warmer than originally expected.
Enceladus was not so icy.
The temperature in the south was enough to melt the ice and turn it into... water.
Scientists cannot give an unambiguous answer to the nature of the origin of this heat.
At the moment, there are two assumptions - either radioactive elements are hidden inside Enceladus,
or heating occurs due to the powerful gravity of Saturn.
But this is not the most important thing.
Another thing is important - Enceladus has water, heat and organic molecules.
And these three components are necessary conditions for... the birth of life!
Perhaps, living organisms unknown to mankind are hiding just a few meters under the ice
on Enceladus.
They feed on dissolved organic compounds and reproduce by some kind of DNA analogue unfamiliar
to humans.
Unfortunately, Cassini's cameras cannot see through the ice.
Therefore, this mystery remains unsolved.
Other expeditions will have to find out if there is life on Enceladus.
In any case, this satellite is currently the most promising place for the search for extraterrestrial
life in the Solar System.
Cassini's mission could not last forever.
Since its launch in 1997, the probe has existed for 20 years.
The last phase of its life was called the "Grand Finale".
It was a suicide mission for science.
The Cassini probe made 22 flights between Saturn and its inner ring, sending priceless
images back to Earth.
And then it headed straight for the gas giant, broadcasting everything live.
And it burned up in the atmosphere of the planet, fulfilling its duty to science until
the last second.
Thanks to the Cassini mission, we got incredible facts about Saturn and its moons.
And, perhaps, we came close to the discovery of the first living form of life in our solar
system.
A new space project Titan Saturn System Mission is already being prepared.
The exact launch date of the project has not yet been disclosed, but it is known that it
will definitely happen before 2029.
After launch, the new space project will follow the path of Cassini and after 9 years it will
approach Saturn.
This time, the mission will not be limited to photographs alone - among the plans of
scientists there is even a task to send samples of Saturn's moons back to Earth!
Perhaps this new mission will provide answers to the questions that we got thanks to Cassini.
We will definitely share this with you.
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