Why is it so difficult to get to Saturn?
Since space exploration began, only four spaceships have managed to reach Saturn.
But, only one managed to enter the planet's bowels and reveal what is hidden under its
cloud-filled atmosphere.
Is it difficult to get to the planet with the giant asteroid rings?
Ready?
Let's get started!
"Introduction" Being the sixth closest planet to the sun,
Saturn is also known for its famous asteroid rings, but despite its fame, few have been
the ships that have managed to reach this distant planet.
The Gas Giants One of the main reasons Saturn is so difficult
for our spacecraft or space exploration probes to visit is that it is part of the planets
known as "gas giants," which are very far from Earth and the sun.
Any spacecraft destined to visit the outermost planets of the solar system must meet specific
requirements that are very difficult to achieve.
One such requirement is that the spacecraft must have a nuclear battery that provides
it with electrical power for all its data transmission functions.
These ships must carry this type of battery instead of the classic solar panels because
these planets are too far from the sun; because of this, very little light arrives, and the
solar panels fail to provide enough energy for the operation of the ship.
Due to the lack of light, it is necessary to incorporate batteries that work with nuclear
thermal energy.
Still, the problem with these batteries is that they weigh a lot, which considerably
increases the cost of the spaceship, in addition to the fact that the heavier it is, the more
fuel is also needed to take it very far, compared to the energy needed by exploration probes
that use solar panels.
Gas giants like Saturn are located beyond the asteroid belt; in these regions, the temperatures
are very, very low, which is why the ships that are sent to explore these planets must
have isolation systems to the low temperatures of the interplanetary medium.
And, of course, one of the most important reasons why it is tough to reach Saturn is
that it is 1,300 million kilometers from Earth.
To cover this distance, a large amount of energy and fuel is necessary at the time of
launch, which is why the probes that have visited Saturn have been supported with the
gravitational assistance of Jupiter.
Too far for telescopes Seen from Earth, Saturn appears as a yellowish
object and one of the brightest in the night sky.
Observed through a telescope, the two most giant rings, classified as A and B, are easily
seen.
The two most minor, classified as D and E, are only seen under optimal atmospheric conditions.
Before the invention of the telescope, Saturn was just another planet in the sky; it was
known to be the farthest of all, but there was no more information about it, nor about
its asteroid belts.
Galileo was the first to observe the rings in 1610, but the low inclination of the rings
and the low resolution of his telescope made him think at first that they were large moons.
Using better observation tools, Christiaan Huygens could clearly observe the rings in
1659.
In 1859 James Clerk Maxwell showed mathematically that rings could not be a single solid object
but must be the grouping of millions of smaller particles.
Today we know that the particles that makeup Saturn's rings are composed mainly of fragments
of rock and ice and that they rotate at a speed of 48,000 km / h. 15 times faster than
a bullet.
Missions to Saturn Four American spacecraft greatly increased
knowledge of the Saturn system: the Pioneer 11 probe, Voyagers 1 and 2, and the Cassini-Huygens
space probe.
These spacecraft carried cameras and instruments to analyze the intensities and polarizations
of radiation in the electromagnetic spectrum's visible, ultraviolet, infrared, and radio
regions.
They were also equipped with instruments for the study of magnetic fields and the detection
of charged particles and interplanetary dust grains.
Pioneer 11 The first spacecraft in history to visit Saturn
was Pioneer 11; this was one of the first probes of NASA's space exploration program.
It was launched from Cape Canaveral on April 5, 1973.
After successfully traversing the asteroid belt on April 19, 1974, its velocity was adjusted
to place its trajectory close to Jupiter.
During its flyby of Jupiter on December 4, 1974, it imaged the Great Red Spot, made the
first observations of the polar regions, and determined the mass of the satellite Callisto.
On September 1, 1979, he arrived at Saturn, taking the first close-distance photographs
of the planet, where he discovered two new satellites and other rings.
After its encounter with Saturn, it continued its route outward from the solar system, studying
the solar wind's energetic particles.
Unsurprisingly, the Pioneer probes got their energy from a radioactive isotope source (RTG)
instead of solar panels.
These generators kept the ships on, so once they ran out, they stopped working in 1995.
As was done with the Pioneer 10 probe and with the Voyager spaceships later, the Pioneer
11 probe included a plaque on its structure explaining the probe's origin to a possible
extraterrestrial culture.
The plaque includes a figure of a man, and a woman, the transitions of the hydrogen atom,
and the position of the Sun and Earth in the galaxy, which was intended to send a message
from the human race to a hypothetical extraterrestrial race that will find the ships in the future
and manage to decipher the information contained in the disks.
Voyager 1 and 2 Before space exploration, only Saturn's largest
satellites, such as Titan, Enceladus, Tethys, Dione, Japeto, or Mimas, were known.
Still, the exploration probes Voyager 1 and 2 managed to make important discoveries about
these satellites that until then were unknown.
Among these discoveries, it was possible to confirm the existence of large amounts of
Methane in the largest moon of Saturn called Titan; they also managed to observe huge geysers
shooting large amounts of ice and water on the satellite Enceladus.
Both Enceladus and Titan are fascinating objects for planetary scientists since the first belief
in the possible existence of liquid water at a shallow depth of its surface, based on
the emission of water vapor in geysers, and the second presents an atmosphere rich in
Methane and similar to that of the primitive Earth.
Likewise, the first high-definition images of Saturn were also taken, which showed a
yellowish color with black lines of storms that occurred in its atmosphere.
Cassini – Huygens This was Saturn's most prolific and longest-lasting
mission on this planet.
This spacecraft discovered two new satellites, Metone and Palene, which are very small and
have irregular shapes.
After discovering these two satellites, Cassini flew by the moon Phoebe taking several pictures
of its surface and making several measurements that helped us know that this tiny moon of
Saturn could have water below its surface.
Titan Exploration The Cassini-Huygens space probe bore that
name because, in addition to an orbiter, it also carried a terrestrial exploration spacecraft;
this was the Huygens probe that would undock from Cassini to land on the surface of Titan,
Saturn's largest moon.
On January 14, 2005, the Huygens probe successfully descended on Titan's surface in a region known
as Adiri, obtaining images during its descent and on the surface.
The panorama during the descent shows gentle hills with drainage channels.
The channels seem to lead to a close, wide, flat, and dark region where you can see an
area of coastline and even islands and what appears to be a sea of methane, all in a foggy
and arid environment.
ESA scientists estimate that the probe could have descended over Titan's dark region.
The image taken after landing shows a flat surface covered by stones in the form of rounded
pebbles.
The pebbles could be mostly made of water ice.
It should not be forgotten that, on Titan, there is no liquid water on its surface, although
there is frozen water; Such ice is present in the form of rocks.
A week after landing, Martin Tomasko of the University of Arizona, responsible for the
Huygens cameras, said: "We now have the key to knowing what shapes Titan's landscape.
The geological evidence of precipitation, erosion, mechanical abrasion, and river activity
that has shaped Titan is much like that which shaped the Earth in the past."
Photos of Titan taken by the probe show a complex network of narrow drainage channels
that descend from the bright mountains to flat, darker lower regions.
There are lakes, coasts, and islands strikingly similar to those on Earth, and it even rains,
though not water like on Earth, but methane.
But the similarities with Earth end here.
Titan is a world ruled by its low temperatures of –179 °C with an atmosphere of nitrogen
and methane.
Their methane fulfills the role of water on Earth, forming clouds in its atmosphere; When
it condenses, it forms a methane shower with particles that fills the torrents with a flowing
black material.
But now the canyons and lakes are dry because methane, like water on Earth, infiltrates
under Titan's soil, leaving traces of organic matter on the surface.
Exploration of Enceladus Following the encounters of the Voyager probes
in the early 1980s, planetary scientists postulated that Enceladus might be geologically active,
given its high albedo (indicating a relatively young surface) and its location in the center
of the E ring.
perhaps through a mechanism of water vapor escape from inside.
In 2005 data obtained through several instruments on board the Cassini probe confirmed this
hypothesis.
In addition, he also found possible reserves of liquid water at shallow depths that erupt
as geysers on the surface of Enceladus, which was one of the most important discoveries
not only of the mission but of the history of space exploration.
Cassini's high-resolution images show icy jets and high ice spikes ejecting large particles
at high speed from Enceladus' surface.
Several models have been considered to explain this process.
Data and models show that the jets escape from liquid water deposits shallow from the
surface.
The proof in favor of a subsurface ocean of liquid water between 30 and 40 kilometers
below the surface is that this moon is growing.
However, a suggested alternative to such an ocean may be large ice caverns filled with
water.
More recent models show that its geological activity is incompatible with the fact that
it is controlled solely by tidal forces.
It is better explained by assuming the existence of such a geological feature, which makes
this small moon an ideal target for the search for extraterrestrial life.
The end of Saturn's exploration The Cassini – Huygens mission was the last
to explore the planet Saturn; this mission ended in 2017 when the spacecraft began to
run out of power, and scientists thought of many options to end it, from sending it to
wander through space to crashing it into Saturn to avoid any biological contamination with
other satellites that could have life.
In the end, it was decided to impact the probe against Saturn, as happened with the Juno
and Galileo probes once its mission in Jupiter was over; in this way, it took advantage of
a gap that exists between the planet and the ring of asteroids that surrounds it and after
making 20 orbits, it rushed against Saturn, burning in its atmosphere and becoming dust.
This option was also taken to take advantage of the systems of the ship that were still
working; thanks to this, they were able to obtain important data about the clouds of
Saturn that today help us understand a little better how this gas giant works.
Today there are no more spacecraft exploring Saturn, but a new mission called Dragon Fly
is being planned, sending a robotic drone to explore Titan's surface in 2027.
Would you like us to make a video about this space mission?
Let us know what you think in the comments!