Is it challenging to get to Jupiter? Why have we never seen
its interior? - E' difficile raggiungere Giove? Perché non abbiamo mai visto il suo interno?
Jupiter is the most visited gaseous planet of all; throughout the history of space exploration,
it has been visited by nine spacecraft; however, so far, only one ship has managed to cross its
dense atmosphere to observe its interior. Is it tough to land a spaceship on Jupiter?
What's inside the gas giant? Ready? Let's get started!
The problem with speed Jupiter is the fifth closest
planet to the sun, but it is not so complicated to get there despite being very far away.
Because is the fact that it is the planet with the highest mass, its gravitational attraction force
is vast, and thanks to that, the spaceships do not work hard once they enter their gravitational
field, but this is also a problem. Getting to Jupiter is relatively easy,
but putting something into orbit around the giant planet is a more significant challenge.
In 1979, the Voyager space probe took 1546 days to reach Jupiter,
but to get so far, the spacecraft had to acquire a very high speed;
a ship traveling so fast cannot remain in orbit around any planet since it will follow its course.
To place a spacecraft in orbit around any celestial body, it must adjust its speed; it must
not go too fast to escape the gravitational pull or too slow to be trapped by gravity and plunge
into free fall towards the surface of the planet. The Voyager probe was too fast to be captured by
Jupiter's gravity. To get into orbit, it would have to make use of rockets to help it slow
down slowly, but at that time, the Voyager probes did not have such rockets equipped.
Future missions that reached Jupiter did count on these rockets to slow
down and enter orbit around the gas giant. Requirements to reach Jupiter successfully
In general, flights to other planets in our solar system are accompanied by high
energy expenditures. For a spacecraft to reach Jupiter's orbit from Earth's,
it requires about the same amount of energy that it would require to lift it off Earth's
surface and place it in low-Earth orbit. However, gravitational assistance can
sometimes be used to help space probes, requiring less energy at launch,
although this procedure significantly increases the time of the mission, which eventually means
that the spacecraft must be equipped with some resource that allows it to replenish energy
during the long journey. Either with solar panels or thermal nuclear energy sources.
An even bigger problem is that Jupiter has no solid surface on which to land;
because of its gaseous composition, there is a smooth transition from its atmosphere and its
inner fluid, but the atmosphere is so large and heavy that any space probe descending through
Jupiter's atmosphere would eventually be destroyed by the immense pressure and reduced to dust.
Another problem is the amount of radiation a probe is exposed to reaching the planet,
given the harsh particle charges around Jupiter. For example, the Galileo probe has orbited it
for several years and has markedly exceeded the amount of radiation for which it was designed. As
a result, the scanning probe has suffered various technical problems and failures attributed to
unrepaired radiation effects. Our visits to Jupiter
Pioneer 10 and 11 (1973 and 1974) Pioneer 10 was the first space probe to
explore Jupiter, which did so in December 1973, followed by Pioneer 11 thirteen months later.
The Pioneer 10 probe was the first spacecraft in history to take the first images of Jupiter from
up close, thanks to which we could observe that Jupiter was covered with storm clouds
that could not be seen clearly from Earth. Pioneer 10 also took images of the Galilean
satellites Europa Io, Callisto, and Ganymede; He observed its atmosphere and radiation belts,
which extend several thousand kilometers from the planet. Thanks to this mission, Jupiter's magnetic
field was detected, which extends so far that all the solar system planets could fit inside it.
Another discovery that we owe to the Pioneer probes is that thanks to temperature lenses,
it was possible to corroborate that Jupiter is mainly liquid, that is to say,
that instead of being called a gaseous planet, it should be called a liquid planet since its
main composition is metallic liquid hydrogen. Pioneer 11 was the first probe to take sharp
images of the Great Red Spot. It made the first observations of its polar regions and obtained
the first close images of the satellite Callisto, which is wholly covered with active volcanoes.
Voyager 1 and 2 (1977 and 1979) The famous Voyager exploration probes
traveling to the solar system's far reaches also used Jupiter's gravity to gain speed.
Voyager 1 began photographing Jupiter in January 1979 and made its closest approach on March 5,
349,000 km from the planet's center. Because of its higher resolution and
shorter distance, most observations of moons, rings, magnetic fields, radiation,
and the environment were made during the two days the probe was closest to the planet.
The Voyager missions improved the understanding of the Galilean satellites.
They contributed to the discovery of the Rings of Jupiter that, until then,
no one had seen because they are too thin to be detected with a telescope from Earth.
Before the Voyager missions, Saturn was believed to be the only planet with asteroid rings.
The probes took the first images of its atmosphere and revealed that the Great Red Spot is an
anticyclone moving counterclockwise, in addition to other smaller storms near the main one.
These missions discovered the Adrastea and Metis satellites orbiting close to Jupiter's rings,
being the first moons of that planet to be discovered by a spacecraft. The third was Thebe.
Together, the two Voyagers recorded great volcanic activity on the Io satellite (a
total of nine volcanic eruptions, with evidence of others occurring between the encounter with the
two probes), an unexpected discovery concerning Jupiter and becoming the first observation of
active volcanoes in another star besides Earth. In Europa, hundreds of lines were discovered and
initially considered acts attributed to tectonic movements. However, thanks to the photographs of
Voyager 2, it was determined that the true origin of these cracks was because Europa is a moon with
geological activity and that it has at least 30 km of crust in the form of a thick layer of ice, It
is currently thought that beneath all of Europa's ice, there could be an ocean of liquid water.
Ulysses (1992) The Ulysses spacecraft
was designed as a five-year mission to study the Sun's never-before-examined north and south poles.
Ulysses became one of the most prolific contributors to knowledge of the solar wind,
interstellar dust, and the three-dimensional character of solar radiation, far exceeding
the lifespan of its planned mission by 13 years and collecting treasure troves of
data on the solar wind, interstellar dust, and the solar activity cycle.
The spacecraft also performed several technical feats, including an unprecedented gravitational
assist maneuver on Jupiter to launch out of the elliptical plane and enter its solar polar orbit.
After the probe's launch, Ulysses headed to Jupiter. He arrived in February 1992
for the gravity-assist maneuver that placed the spacecraft into its unique solar orbit
that no other spacecraft had done before. Thanks to this, the probe managed to leave
the plane of the ecliptic where all the planets rotate and pass over the south
pole of the Sun in 1994 and the north pole in 1995. Beginning his second orbit of the Sun,
Ulysses revisited the south pole in 2000 and the north a year later. At the time, the Sun was near
the peak of its 11-year activity cycle. Ulysses then returned to Jupiter's orbit on the long
stretch of its six-year circuit around the Sun. The mission ended on June 30, 2009, after
disconnecting the probe remotely, unable to carry out further significant scientific activities due
to the depletion of its nuclear power source. Galileo (1995)
So far, Galileo has been the only space mission to venture deep into Jupiter. During the mission,
a large amount of information was gathered about the planet and its system. However,
it was not as large as expected due to a failure in deploying the probe's transmitting antenna.
Significant events during the eight years the mission covered included multiple flybys of all
Galilean moons, including Amalthea, the first probe to do so. In part,
it witnessed the impact of comet Shoemaker-Levy 9 as it approached Jupiter in 1994 and sent back
atmospheric proof of the planet in December 1995. An atmospheric probe was deployed from Galileo
in July 1995, which entered the planet's atmosphere on December 7 of that year.
After descending with an immense g-force, it was destroyed by atmospheric pressure
and temperature after crossing 150 km of the atmosphere and collecting data for 57.6 minutes.
The probe was subjected to 22 times the Earth's temperature, at 153 °C. It is believed that the
probe was melted down and probably evaporated by the high temperatures turning into dust.
Later the Galileo probe ran with the same fate, although more quickly,
after being deliberately directed toward the planet at (50 km / s) to prevent any failure
to cause the probe to fall on the satellite Europe, contaminating it with human space debris.
Among the scientific results obtained by Galileo is the first observation of ammonia clouds in the
atmosphere of a planet other than our own; The atmosphere creates clouds of ammonia ice from
materials from the depths. He also confirmed the extensive volcanic activity that was suspected
on Io, a hundred times greater than the Earth, considering the heat and its frequency as an
example of what the Earth was in the past; on this moon, he also observed the complex plasma
interactions of the atmosphere, which give rise to electric currents similar to Earth's
thunderstorms, but thousands of times larger. He also provided evidence confirming the existence
of a liquid ocean under Europa's surface ice. He made the first detection of a large magnetic
field around a satellite (Ganymede), something completely unprecedented since, until then,
it had never been seen that a satellite could have such a large magnetic field.
The Galileo probe also provided evidence of magnetic fields suggesting the presence of
salty oceans beneath the surface of Europa, Ganymede, and Callisto, as well as a thin
atmospheric layer on all three moons, called the exosphere, indicating that all three satellites
have a high probability of harboring both liquid water and possible living things inside.
Cassini-Hyugens (2000) In 2000, on its journey to Saturn, Cassini-Huygens
approached the planet, providing some of the highest-quality images of Jupiter to date.
One of the main findings of the space mission was announced on March 6, 2003, about the atmospheric
circulation of Jupiter; The dark belts alternate with the illuminated areas of the atmosphere.
For a long time, scientists believed that the areas, with their pale clouds,
were the regions from which air emerged into the outer atmosphere,
similar to how it happens on Earth. However, analysis of Cassini-Huygens images shows that
individual storm cells arise in bright white clouds, too small to be seen from Earth.
New Horizons (2007) On its journey to Pluto,
New Horizons approached Jupiter for gravitational assistance. While on Jupiter,
he made detailed measurements of the inner moons, in particular, Amalthea; He measured the volcanoes
of Io and studied the Galilean satellites, as well as other moons such as Himalia and Elara.
The probe also studied the planet's Little Red Spot, magnetosphere, and thin ring system,
as well as taking infrared images that helped better understand its atmosphere.
Juno (2011) The last mission
to reach Jupiter was Juno; this probe was designed to study the planet's atmosphere,
origin, structure, and evolution within the solar system and, thus, better understand its formation.
Its main functions are focused on creating a study and map of gravity in its magnetic fields,
Jupiter's auroras, and its magnetosphere. It will also study clues about the planet's formation,
its core, water in the atmosphere, its mass, and its winds, which can reach speeds of up
to 618 kilometers per hour (384 mph). Currently, the Juno probe continues to
orbit Jupiter on a safe trajectory that protects it from the intense radiation
emitted by the gas giant and is expected to continue operating for at least six more years.
When Juno's mission ends, it will have the same fate as Galileo;
it will intentionally crash into Jupiter so that it does not contaminate other satellites,
such as Europa, which can harbor water. According to experts, future missions
to Jupiter will not be to study the gas giant but to study its moons; in fact,
the European Space Agency already has a date for such a mission and is called JUICE which
means Jupiter Icy Moons Explorer, a mission that will take off in April of this year and that will
aim to make detailed observations of the gas giant planet and its three large oceanic moons
(Ganymede, Callisto, and Europa) with a set of remote sensing instruments for organic matter.
The mission will characterize these moons as planetary objects and possible habitats that
could be humanity's following settlements. Would you like us to make a video about the
future JUICE Mission that will explore Jupiter's moons? Let us know what you think in the comments!