What's so strange happening on Jupiter?
On earth, hurricanes last a few days, but on Jupiter, there is a storm that has not
stopped for almost 400 years. This is Jupiter's great red spot, a colossal storm 9942 miles
(16,000 km) wide and holding incredible mysteries. What feeds this massive hurricane,
and why does it have that color? Will it disappear one day? Let's find out!
"Introduction" It
isn't easy to get an idea of its enormous proportions.
The Great Red Spot is the diameter and longest-lasting storm in the Solar System,
with a diameter larger than our planet. Its clouds rise 5 miles (8 km) above Jupiter's other clouds.
Hurricane-force winds whip the edge of the storm at more than 250 miles per hour (400 kilometers
per hour). And it is not a temporary phenomenon: while storms on Earth usually last a few days,
this storm has been active for at least 350 years. SINCE WHEN DOES THE GREAT RED SPOT EXIST?
In 1664 the English scientist Robert Hooke was the first to claim that he had observed a spot
on Jupiter. But that spot was near the planet's north pole, so astronomers thought it could not
be the same one we know today as the Great Red Spot, located in the southern hemisphere.
In 1713 the Italian astronomer, Giacomo Maraldi, observed the red spot again. Two years earlier,
the painter Donato Creti had painted a series of oils of celestial bodies
that included a painting of Jupiter with a big red spot in the south but without the
red spot in the north that Hooke had seen. Did it mean that astronomers had seen two
different spots in the last 400 years? No, the answer was more straightforward. What happened
was that the ancient telescopes reversed the images they took. That is, the spot that Hooke
saw in the north of Jupiter was actually in the south, so we have seen the same spot all the time.
There was no reference to Jupiter's Great Red Spot for more than a century. It is strange
that the great astronomers of the second half of the eighteenth century, such as William Herschel,
overlooked the existence of the Great Red Spot. That is why some experts raise the
possibility that the Great Red Spot suffered a change in color or a decrease in size at that
time that helped it go unnoticed by astronomers. The modern history of the Great Red Spot began in
1831 when German astronomer Samuel Heinrich Schwabe depicted it in detailed drawings.
In 1878, the American astronomer Carr W. Pritchett baptized this formation with its current name, and
since then, this fascinating formation has been observed regularly and with increasing precision.
WHAT IS THE GREAT RED SPOT? To better understand the nature
of this phenomenon, scientists have tried to compare it to storms on Earth.
Cyclones on Earth can reach more than 620 miles (1,000 kilometers) in diameter,
with winds reaching speeds of 186 miles per hour (300 kilometers per hour).
They can raze entire cities and wreak havoc in their wake in hours.
This power, however, is insignificant compared to that of the Great Red Spot.
From the meteorological point of view, the Great Red Spot is an anticyclonic storm;
that is, the pressure in the center is bigger than in the periphery. It has a slightly oval
shape and rotates counterclockwise with a period of six Earth days.
As in the hurricanes of our planet, its center remains relatively calm, with pretty mild winds.
However, in the periphery, the situation is very different: the average wind speed is 250 miles
per hour (400 kilometers per hour), reaching peaks of 373 miles per hour (600 kilometers per hour).
The Great Red Spot remains fixed in latitude (north-south position) but
moves in longitude concerning the clouds, dragged by the planet's rotation. That is,
storms on Jupiter rarely move from north to south; they only do so from left to right.
On Jupiter, storms are formed by the same gases; that is, the variation of color depends mainly on
temperatures and not so much on the materials that make up the clouds. Sometimes it has an
intense and very noticeable ingrown color, and sometimes it pales until it becomes insignificant.
Suppose we compare the storm of Jupiter with those of the rest of the gaseous planets.
In that case, we realize this phenomenon is unique since Saturn has the so-called Great White Spot.
This periodic storm appears in the northern hemisphere or the tropical zone, characterized by
its white color, a core the size of the Earth, and a tail of several thousand kilometers in length.
Saturn's white Spot was first seen in 1876, and six of these storms have been observed
in the last 140 years, most recently in 2010. Unlike Jupiter's Spot, this one only lasts a
few years. Although the cause is unknown, storms usually occur when Saturn's northern hemisphere
is oriented toward the Sun. Their appearance is related to the cooling of the Saturnine
atmosphere during the winter, although that doesn't explain why they're so rare.
Similar in appearance to Jupiter's Great Red Spot, there is Neptune's so-called Great Dark Spot,
which was detected in that planet's southern hemisphere in 1989 by the Voyager 2 probe. The
spot was almost the same size as Earth, and around it, winds were measured with speeds close to 1500
miles per hour (2,415 kilometers per hour), the fastest ever recorded in the Solar System.
When the Hubble Space Telescope wanted to photograph it in 1994, the Great Dark Spot
completely disappeared, leaving scientists with doubts about its true nature. Was it a hole in
Neptune's immense methane atmosphere, similar to Earth's ozone hole? Or a storm that dissipated?
What do you think it was? Let us know your opinion in the comments.
Since then, four other similar dark spots have been observed in Neptune's atmosphere. These spots
can appear in any region of the planet and last about two years until they disappear due to the
powerful winds in the atmosphere's upper areas. Nothing compared to Jupiter's Great Red Spot and
its record of permanence over several centuries. WHY DOESN'T THE BIG RED SPOT GO AWAY?
Jupiter's atmosphere abounds with large storms and the frequency of rotating winds, including the
Great Red Spot. At a size of 9942 miles (16,000 km) wide, this storm is more extensive than Earth.
The exciting thing is that while a storm lasts a few days on Earth, on Jupiter,
this storm has existed for centuries. From a scientific point of view,
it is puzzling how the storm can last so long and be so large, and it is also unclear whether these
storms are limited to the highest parts of the planet's atmosphere or extend inland from it.
Thanks to data collected by NASA's Juno space probe,
experts analyzed the vertical structure of the Great Red Spot, as well as two other storms.
They found that they extend below the altitude at which water and ammonia,
or the planet's cloud level, are expected to condense. This is unique to the Great Red Spot.
In addition, data collected by the Juno exploration probe showed a strange
gravitational anomaly just above the Great Red Spot. This means that below the spot,
there is a large concentration of mass that accumulates and feeds the storm.
It must also be considered that the Earth has a solid surface, so any storm loses energy due to
friction with the ground. That is why cyclones and hurricanes in the sea usually weaken when
they land and disappear in a few days. In contrast, Jupiter has no solid surface. Its
gaseous atmosphere becomes denser with depth, so a storm can continue to grow because there
is no friction with the ground to stop it. DO YOU WANT THE RED SPOT TO APPEAR ONE DAY?
Thanks to the Juno mission, launched to study Jupiter's interior, we are expanding our
knowledge about the Great Red Spot. For example, we know that the storm's roots penetrate more than
186 miles (300 kilometers) into the planet's atmosphere. Experts say this is much more than
expected and is between 50 and 100 times the depth of our planet's oceans. This depth is, in turn,
responsible for the powerful currents that are generated around it. In general, these currents
are associated with temperature differences. These discoveries indicate that the base of
the Great Red Spot could be in the interior of Jupiter and be much hotter than the top.
Even so, there is still much we do not know about the Great Red Spot. The fluid mechanics
that govern this storm are very complex. Not even using the computing power of current
computers can we simulate it accurately. It is known that the Great Red Spot also
feeds on other small spots that form in the area between the two adjacent bands. But it
is unknown what real engine has kept the Great Red Spot active for so long.
Scientists are confident that data from the Juno mission will help clarify the issue. This way,
we could better understand how the turbulent atmospheres of Jupiter,
Saturn, and giant planets work in general. Recently, a team of scientists led by researcher
Michael Wong discovered that Jupiter's Great Red Spot is moving faster and faster. Specifically,
the researchers divide the storm into two parts, an outer ring and an inner ring,
of which the former continues to gain speed over its internal counterpart.
After analyzing more than ten years of data obtained by Hubble, researchers have found that
the wind speed of its outer ring has increased by up to 8% between 2009 and 2020. In contrast,
winds near the innermost region of the Great Red Spot are moving significantly slower.
Does it mean that the Great Red Spot is growing rather than disappearing?
According to Wong, that's hard to diagnose, as Hubble can't observe the bottom of the storm.
Anything below the top of the clouds is invisible in the data; therefore,
we cannot deduce what will happen shortly. Astronomers have conducted studies of the solar
system's "great storm queen" for centuries, and most agree that the Great Red Spot is an
outcrop of material from Jupiter's interior. If we were to look at it from the side, the
storm would have a structure very similar to that of a wedding cake, staggered, with high clouds in
the center cascading towards its outer layers. Astronomers have found that, for over a century,
it has been shrinking in size and becoming more circular and small, giving the impression that
it is disappearing. However, the new Hubble data opens a new possibility that the famous
Jupiter storm still has many years to go. It is impossible to know if the Great Red
Spot will disappear in a few decades or if it will recover from resurfacing with more force,
as perhaps in the eighteenth century. Its evolution over the next few years
will be the key to clearing the future of the storm. In the worst-case scenario,
the disappearance of the Great Red Spot would be a loss equivalent to the disappearance of
Saturn's rings or Mars' polar ice caps. It would be a shame if this happened, but the truth is that
nothing lasts forever. And as popular wisdom states, after the storm always comes calm.