Interesting Facts About Jupiter’s Red Spot
- The Great Red Spot of Jupiter is an extra-terrestrial storm that has been churning the gas giant for more than a hundred years.
- The first official record of the Jupiter Red Spot was that of a drawing by Samuel Heinrich Schwabe in 1831. Though not sure, it could also be the same storm that was discovered way back in 1665.
- Jupiter’s persistent storm earned its name because of its overall reddish color. However, the reason why it is red is still unknown. It has an oval shape that is big enough to swallow Earth.
- While the Earth is 12,742 km (7,918 miles) in diameter, the Great Red Spot measures around 16,350 km (10,159 miles). That means this storm is 1.3 times as big as our home planet!
- Though it is bigger than Earth, the Great Red Spot is actually shrinking. It is getting smaller by around 900 km (559 miles) per year. To compare, around the 1800s, it was believed to be about three times as wide as Earth. Now, it is only slightly bigger.
- The Great Red Spot produces winds around 430–680 km/h (270–425 mph). This is much stronger than the strongest hurricanes that hit Earth, which have maximum speeds of around 281 km/h (175 mph).
- Though it is called the Great Red Spot, this storm changes color. Aside from being red, it can be as dark as brick red and as light as pale salmon. There are times when it can also be white.
Jupiter’s Great Red Spot: The Biggest Storm in the Solar System
- Size: 16,350 km (10,159 miles)
- Location: Jupiter’s south equatorial belt (22° S)
- Movement: counterclockwise
- Rotation: 6–7 Earth days (14 Jovian days)
- Wind speed: 430-680 km/h (270-425 mph)
Jupiter is the fifth planet from the Sun and is a wonderful system of its own. This gas giant is surrounded by 79 moons. Also, it shares its orbit with the interesting minor planets called trojan asteroids.
Aside from these objects, there is also something big that is happening on the king of the planets itself—the Great Red Spot!
The Great Red Spot is a massive storm located 22° in the southern hemisphere of Jupiter. It is an anticyclone with the wind circulating on a high-pressure center. The storm moves counterclockwise, with a rotational period of roughly 7 Earth days.
To see just how big this storm is, let us put the size of the Earth into context. Earth is 12,742 km (7,918 miles) in diameter while the Great Red Spot is around 16,350 km (10,159 miles). That means, we can fit about 1.3 Earths on this enormous vortex.
When it was first observed, around halfway through the 1800s, it was said that the storm could engulf about three Earths. That means the Great Red Spot is getting smaller. Since it is smaller, the rotation period of this storm has also decreased over time.
Nevertheless, despite years of observation, there is still much to learn about this colossal storm.
A Large, Deep, and Long Lasting Storm
A spot was observed on Jupiter from 1665 to the early 1700s. If it is the same storm, then the Great Red Spot has been around for more than 300 years.
There is no conclusive evidence, however, that it was indeed the same spot. Formal observations of the Jupiter Spot started in September 1831. And from then on, in 1878, continuous monitoring began.
The Great Red Spot is situated between Jupiter’s northern and southern atmospheric bands. The northern band is moving eastward while the southern band is moving westward. These opposing bonds formed the great storm and have sustained it for hundreds of years.
Sometimes, it swallows smaller storms as well, which keeps it spinning and makes it even more powerful.
Observations from the late 1870s show that this storm becomes smaller and taller. It goes deeper by more than 320 kilometers (200 miles) into the atmosphere of the giant planet. This means that it extends way deeper than any storms on Earth which are about 15 km (9 mi) from top to bottom. The Red Spot has also changed into a darker orange color over time.
Enormous storms have also been observed on other planets, but none has been as long-lasting as the Jupiter Red Spot. Examples are the Great Dark Spot of Neptune and Saturn’s Great White Spot.
Great Red Spot Location
Jupiter’s Great Red Spot is located 22 degrees south of its equatorial region. By looking at pictures of the planet, we can easily see it as a reddish oval in the southern hemisphere of the gas giant.
This swirling storm does not only occur in the upper atmosphere of Jupiter. As NASA’s Juno spacecraft reveals, it goes deeper around 500 kilometers (310 miles) from the cloud tops.
Discovery and Observations Through Time
Jupiter has been known since antiquity because it is the third brightest object in our night sky, after the Moon and Venus. It is hard to miss because it has an apparent magnitude of -2.2.
Even though people can easily see Jupiter by looking up at the sky, it was only in 1610 that the gas giant was observed in detail. The famous Italian astronomer Galileo Galilei invented a telescope that was more advanced than the telescope of his time. He turned it toward Jupiter and he saw its four major moons: Io, Callisto, Europa, and Ganymede.
The Great Red Spot makes Jupiter an even more interesting subject for astronomical observations. In 1831, astronomer Samuel Heinrich Schwabe made the first detailed drawing of this storm. From then on, many observations have been made on the Red Spot.
In the earlier years, in 1665, Giovanni Cassini also observed a spot on the planet. He described it as a “permanent spot.” It could be the same storm, but astronomers are not able to confirm it.
As it turned out, the “permanent spot” was not very permanent. It was last observed in 1713 and the Great Red Spot was seen around 1830s. The long gap in the observations of these phenomena makes it difficult to confirm if they are indeed the same spots.
So Why Is It Red?
The great storm of Jupiter was depicted in red color for the first time in 1711. It was seen in a painting by Donato Creti which is now placed in the Vatican Museums. Before that, the Jovian storm was not illustrated in any color.
There are still many questions surrounding the Great Red Spot—and one of them is why it is red.
The reason for its reddish color is still a big mystery. However, through laboratory experiments, scientists think it has something to do with the compounds surrounding the planet, particularly ammonia. Cosmic rays, which are an ever-present radiation in space, also play a role in this.
Jupiter’s upper atmosphere is composed of ammonia, with ammonium sulfide clouds below. Water forms the lower level of the clouds. White clouds are produced from these three which, when hit by radiation, split into molecules that can combine to form red-looking compounds.
In 1973, Pioneer 10 made the first flyby of Jupiter. It opened up a whole new understanding of Jupiter and its system. This flyby obtained photos of the Galilean moon and the Great Red Spot, among others.
The Voyager 1 spacecraft made the next flyby in 1979 which brought us the first close-up look of the Red Spot. It revealed that there is a lot going on in this storm and that the planet has many other smaller storms. From this flyby, we also know that it is moving in a counterclockwise direction.
The Juno mission gave us the most detailed look into the Great Red Spot yet. It made a close approach to Jupiter in 2017 and took interesting images of the famous storm. Because of this flyby, we learned that the Great Red Spot is not only big, but it is also deep.
Shrinking But Speeding Up
Since it has been monitored since 1879, astronomers are able to compare data on the Great Red Spot in the present to how it was a hundred years ago or so.
Around the turn of the 19th century, the spot was around 48,000 km (30,000 miles) wide. At the time of Voyager 1’s visit in 1979, the spot had a length of around 23,000 km (14,300 miles). Aside from becoming smaller, it also seems to be dissipating around the edge.
The Great Red Spot was known for its oval shape but observations show that it is becoming more and more circular as it shrinks. As observed by an amateur astronomer in 2019, it also seems to be “flaking.” Each year, it gets smaller by about 900 km (559 miles). And at this rate, it is projected to become circular by the year 2040.
Although this long-lasting storm is becoming smaller, it has also become stronger, as seen by NASA’s Hubble Space Telescope. Data from the years 2009 to 2020 indicate that the winds on the outer ring of the storm are accelerating. Called the “high-speed ring,” wind speeds in this zone are now around 650 kph (400 miles per hour).
Determining this change was possible because of 11 years worth of data from the Hubble Space Telescope. As of yet, it is the only telescope with this kind of coverage, said Amy Simon (NASA’s Goddard Space Flight Center).
These small changes, which are less than 2.6 km (1.6 miles) per hour per Earth year, would have remained undetected if not for the records of the past decade or so. Even the team that worked on this analysis cannot believe it. As Micheal Wong of the University of California, Berkeley, said, “no one has ever seen this before!”
The central region of the Great Red Spot has a different story to tell. While the outer zone is speeding up, the winds around the center are rather decreasing in speed.
Red Spot Jr. and Other Jovian Storms
In addition to the Great Red Spot, Jupiter is also home to several smaller storms and eddies. One of these is called Oval BA, which is nicknamed the Little Red Spot or Red Spot Jr. after the eponymous storm.
Just like the Great Red Spot, Red Spot Jr. is also located in the southern hemisphere of Jupiter. It was formed after three storms collided, and was first observed in 2000. Since then, it has become more powerful.
First seen as a white storm, Oval BA started turning red in 2006. In the same year, planetary scientist Amy Simon of NASA and her team used the Hubble Space Telescope to photograph a close passage of the Great Red Spot and Red Jr.
Another close encounter happened in 2008, but this time, with a third smaller spot. This new storm was nicknamed “baby red spot.” It was in the same latitudinal band as the Great Red Spot.
From May to July 2008, these three storms had an encounter that ended up with the baby red spot being swallowed by the Great Red Spot. Red Spot Jr., which is located just below, remained unscathed.
Great Red Spot: Frequently Asked Questions
1. What is Jupiter’s Red Spot?
Jupiter’s Red Spot is a very big storm on the gas giant which has existed for more than a hundred years. Though it is growing smaller, it is still big enough to swallow Earth. It is unlike any other storm we have experienced on Earth, and in the entire solar system.
2. How big is Jupiter’s Red Spot?
The Great Red Spot of Jupiter is about 16,350 km (10,159 miles) across. Since the Earth’s diameter is 12,742 km (7,918 miles), we can fit about 1.3 Earths in this Red Spot. This is indeed a very otherworldly storm that is even bigger than our planet!
3. Where is the Great Red Spot located?
The Great Red Spot is a storm on Jupiter, the fifth from the Sun. It is located 22 degrees in the southern hemisphere of Jupiter.
4. When was the Great Red Spot first observed and who discovered it?
Many spots have been seen on Jupiter but the first official record of the Great Red Spot was on September 5, 1831. This was illustrated by the drawing of German astronomer Samuel Heinrich Schwabe.
Before that, in 1664, Robert Hooke saw a spot on Jupiter, but it was in the planet’s North Equatorial Belt. In 1665, Giovanni Cassini also observed a spot, which was seen until 1713. There is still no way to tell if it is indeed the same Great Red Spot that was seen in 1831 up until now.
5. Why Does Jupiter Have a Red Spot?
Jupiter’s atmosphere is made up of gases—moving and swirling all around. These swirling winds can combine to form bigger storms. This process was seen in the recently-formed storm, Oval BA or Red Jr. The Great Red Spot is thought to have formed the same way.
Red Jr. formed when three smaller white storms merged. Now, it has turned into a reddish color just like the Great Red Spot. Since Jupiter is a gas giant, it has no solid ground to slow down these winds. This is why the storms on gas giants are more violent.
Also, the Great Red Spot swallows smaller storms that come near it. This could be one reason that fuels this gigantic storm, making it last even longer.
Jupiter: By NASA, ESA, and A. Simon (Goddard Space Flight Center) – http://www.spacetelescope.org/images/heic1410a/ or http://hubblesite.org/newscenter/archive/releases/2014/24/image/b/ (Archive), Public Domain, https://commons.wikimedia.org/w/index.php?curid=32799232
A Large, Deep, and Long Lasting Storm: By Kevin Gill from Los Angeles, CA, United States – Jupiter’s Great Red Spot – July 8 1979, CC BY 2.0, https://commons.wikimedia.org/w/index.php?curid=67102754
Discovery and Observations Through Time: By NASA – This image or video was cataloged by Jet Propulsion Laboratory of the United States National Aeronautics and Space Administration (NASA) under Photo ID: PIA02855., Public Domain, https://commons.wikimedia.org/w/index.php?curid=1976022
So Why Is It Red?: By Donato Creti – Pinacoteca Vaticana, Public Domain, https://commons.wikimedia.org/w/index.php?curid=48553214
Jupiter Explorations (Juno spacecraft): https://www.nasa.gov/feature/jpl/nasas-juno-spacecraft-completes-flyby-over-jupiter-s-great-red-spot
Shrinking But Speeding Up: By NASA/JPL/University of Arizona – From http://photojournal.jpl.nasa.gov/catalog/PIA02863, Public Domain, https://commons.wikimedia.org/w/index.php?curid=616873
Red Spot Jr. and Other Jovian Storms: By NASA, ESA, I. de Pater, and M. Wong (UC Berkeley) – This is a retouched picture, which means that it has been digitally altered from its original version. Modifications: Cropped. The original can be viewed here: Grs junior.jpg: ., Public Domain, https://commons.wikimedia.org/w/index.php?curid=2008991
Jupiter’s Red Spots: By NASA, ESA, A. Simon-Miller (Goddard Space Flight Center), N. Chanover (New Mexico State University), and G. Orton (Jet Propulsion Laboratory) – http://hubblesite.org/newscenter/archive/releases/2008/27/image/a/, Public Domain, https://commons.wikimedia.org/w/index.php?curid=4529990