Why Jupiter's Great Red Spot Has Lasted So Long Why Jupiter's Great Red Spot Has Lasted So Long By Charles Q. Choi , SPACE.com Contributor | November 25, 2013 07:01am ET MORE Close-up of Jupiter's Great Red Spot as seen by a Voyager spacecraft. Credit: NASA/JPL-Caltech The mystery of why Jupiter's Great Red Spot did not vanish centuries ago may now be solved, and the findings could help reveal more clues about the vortices in Earth's oceans and the nurseries of stars and planets, researchers say. The Great Red Spot is the most noticeable feature on Jupiter's surface — a storm about 12,400 miles (20,000 kilometers) long and 7,500 miles (12,000 km) wide, about two to three times larger than Earth. Winds at its oval edges can reach up to 425 mph (680 km/h). This giant storm was first recorded in 1831 but may have first been discovered in 1665.

"Based on current theories, the Great Red Spot should have disappeared after several decades," researcher Pedram Hassanzadeh, a geophysical fluid dynamicist at Harvard University,said in a statement. "Instead, it has been there for hundreds of years." [ Photos: Most Powerful Storms in the Solar System ] Vortices like the Great Red Spot can dissipate because of many factors. For instance, waves and turbulence in and around the storm sap its winds of energy. It also loses energy by radiating heat. Moreover, the Great Red Spot rests between two powerful jet streams in Jupiter's atmosphere that flow in opposite directions and may slow down its spinning. Some researchers suggest that large vortices such as the Great Red Spot gain energy and survive by absorbing smaller vortices . However, "this does not happen often enough to explain the Red Spot's longevity," researcher Philip Marcus, a fluid dynamicist and planetary scientist at the University of California, Berkeley,said in a statement. Jupiter, the giant of our solar system, is as fascinating as it is photogenic. How much do you know about the king of the planets? Start Over | More Quizzes The Great Red Spot is not the only mysterious vortex.

In fact, vortices in general, including ones in Earth's oceans and atmosphere, often live much longer than current theories can explain. To help solve the mystery of the Great Red Spot's endurance, Hassanzadeh and Marcus developed a new 3D, high-resolution computer model of large vortices. Models of vortices generally focus on swirling horizontal winds, where most of the energy resides. Although vortices also have vertical flows, these have much less energy. Therefore, "in the past, most researchers either ignored the vertical flow because they thought it was not important, or they used simpler equations because it was so difficult to model," Hassanzadeh said. The researchers now find that vertical flows hold the key to the Great Red Spot's longevity: When the storm loses energy, vertical flows move hot and cold gases in and out of the storm, restoring part of the vortex's energy. Their model also predicts radial flows that suck winds from the high-speed jet streams around the Great Red Spot toward the storm's center, helping it last longer. Together, vortices — whether on Jupiter or in Earth's oceans — may decay up to 100 times slower than researchers previously thought.

"Some vortices in the oceans have been observed to last for several years and are believed to play an important role in the oceanic ecosystem and ocean-atmosphere interaction," Marcustold SPACE.com. In addition, "vortices with physics very similar to the Great Red Spot are believed to contribute to star and planet formation processes, which would require them to last for several million years. Both oceanic and astrophysical vortices are subjected to dissipating processes, and the mechanism described here for the longevity of the Great Red Spot presents a very plausible explanation for their longevity as well." The scientists caution that their model does not entirely explain the Great Red Spot's long life span. They suggest that occasional mergers with smaller vortices may help prolong the giant storm's life as well, and have begun modifying their computer model to test this idea. In addition, their "current model does not account for compressibility of the flow or sphericity of the planet," Hassanzadeh told SPACE.com. "Although we believe that these effects do not change the conclusions of our work, we are planning to modify our model in the next step and include these effects." The scientists will detail their findings Nov.

25 at the annual meeting of the American Physical Society's Division of Fluid Dynamics in Pittsburgh. Follow us @Spacedotcom , Facebook and Google+ . Original article on SPACE.com . Editor's Recommendations Mystery Of Jupiter's Great Red Spot May Have Been Solved At Last | The Huffington Post Mystery Of Jupiter's Great Red Spot May Have Been Solved At Last 12/02/2013 12:22 pm ET | Updated Dec 03, 2013 1.2k Charles Q. Choi Space.com The mystery of why Jupiter's Great Red Spot did not vanish centuries ago may now be solved, and the findings could help reveal more clues about the vortices in Earth's oceans and the nurseries of stars and planets, researchers say. The Great Red Spot is the most noticeable feature on Jupiter's surface — a storm about 12,400 miles (20,000 kilometers) long and 7,500 miles (12,000 km) wide, about two to three times larger than Earth. Winds at its oval edges can reach up to 425 mph (680 km/h).

This giant storm was first recorded in 1831 but may have first been discovered in 1665. "Based on current theories, the Great Red Spot should have disappeared after several decades," researcher Pedram Hassanzadeh, a geophysical fluid dynamicist at Harvard University,said in a statement. "Instead, it has been there for hundreds of years." [ Photos: Most Powerful Storms in the Solar System ] Vortices like the Great Red Spot can dissipate because of many factors. For instance, waves and turbulence in and around the storm sap its winds of energy. It also loses energy by radiating heat. Moreover, the Great Red Spot rests between two powerful jet streams in Jupiter's atmosphere that flow in opposite directions and may slow down its spinning. Some researchers suggest that large vortices such as the Great Red Spot gain energy and survive by absorbing smaller vortices . However, "this does not happen often enough to explain the Red Spot's longevity," researcher Philip Marcus, a fluid dynamicist and planetary scientist at the University of California, Berkeley,said in a statement. The Great Red Spot is not the only mysterious vortex.

In fact, vortices in general, including ones in Earth's oceans and atmosphere, often live much longer than current theories can explain. To help solve the mystery of the Great Red Spot's endurance, Hassanzadeh and Marcus developed a new 3D, high-resolution computer model of large vortices. Models of vortices generally focus on swirling horizontal winds, where most of the energy resides. Although vortices also have vertical flows, these have much less energy. Therefore, "in the past, most researchers either ignored the vertical flow because they thought it was not important, or they used simpler equations because it was so difficult to model," Hassanzadeh said. The researchers now find that vertical flows hold the key to the Great Red Spot's longevity: When the storm loses energy, vertical flows move hot and cold gases in and out of the storm, restoring part of the vortex's energy. Their model also predicts radial flows that suck winds from the high-speed jet streams around the Great Red Spot toward the storm's center, helping it last longer. Together, vortices — whether on Jupiter or in Earth's oceans — may decay up to 100 times slower than researchers previously thought.

"Some vortices in the oceans have been observed to last for several years and are believed to play an important role in the oceanic ecosystem and ocean-atmosphere interaction," Marcustold SPACE.com. In addition, "vortices with physics very similar to the Great Red Spot are believed to contribute to star and planet formation processes, which would require them to last for several million years. Both oceanic and astrophysical vortices are subjected to dissipating processes, and the mechanism described here for the longevity of the Great Red Spot presents a very plausible explanation for their longevity as well." The scientists caution that their model does not entirely explain the Great Red Spot's long life span. They suggest that occasional mergers with smaller vortices may help prolong the giant storm's life as well, and have begun modifying their computer model to test this idea. In addition, their "current model does not account for compressibility of the flow or sphericity of the planet," Hassanzadeh told SPACE.com. "Although we believe that these effects do not change the conclusions of our work, we are planning to modify our model in the next step and include these effects." The scientists will detail their findings Nov.

25 at the annual meeting of the American Physical Society's Division of Fluid Dynamics in Pittsburgh. JUPITER STORMS JUPITER STORMS Big Red and the hot spot Storms 5-28-08 5-30-08 A third red spot has appeared alongside the Great Red Spot and Red Spot Jr. in the turbulent Jovian atmosphere. I left the photo large to enable easy reading. Jupiter Grows Third Red Spot Wednesday, May 28, 2008 A potentially historic change is occurring on Jupiter. An upstart storm now rivals the gas giant's Big Red Spot as king of storms, astronomers announced last week. The Little Red Spot, as it was named upon discovery in 2006, shows both size and speed in threatening to knock the former champion off its perch, with Junior's maximum winds reaching 384 mph (172 meters per second). "In terms of maximum wind speed, the Little Red Spot as measured in 2007 and the Great Red Spot when last measured in 2000 are just about the same," said Andrew Cheng, physicist and lead study author at Johns Hopkins University Applied Physics Laboratory in Laurel, Maryland.

Those winds far outstrip the 156 mph threshold that defines a Category 5 hurricane on Earth, and the Little Red Spot itself appears nearly as big as our whole planet. Seeing spots A third red spot on Jupiter was also announced last week by a different team, joining its larger super-storm cousins. The Great Red Spot has raged on for at least two centuries and perhaps as much as 350 years, ancient observations suggest. Cheng's team used image maps made by the New Horizons spacecraft to gauge wind speed and direction. The Hubble Space Telescope provided visible-light images of the storms, while the Very Large Telescope in Chile used mid-infrared to glimpse the thermal structure of the storms below the visible cloud tops. The thermal heat images showed that the Little Red Spot may already match the Great Red Spot for size, although the latter still appears almost twice as large on the surface of Jupiter's atmosphere when examined in visible light. "In the infrared, which sees deeper beneath those clouds, the Little Red Spot appears to be part of an interacting system that is actually larger than the Great Red Spot," Cheng told SPACE.com. The Little Red Spot has steadily gained strength even as the Big Red Spot shrinks.

Both storms have winds that circulate in the opposite direction to that of a cyclone, or counterclockwise, and appear "strikingly similar," Cheng said. Seeing red Astronomers remain mystified by the angry red color of the storms. The Little Red Spot only changed color in late 2005 after it formed from earlier mergers of three smaller storms. Similarly, the newest third red spot began as an oval white storm. These latest findings support the theory that the most powerful storms dredge up material from below Jupiter's clouds and lift it into the upper atmosphere. That exposes the material to solar ultraviolet radiation and causes the color change to red. The newcomer storm may end up merging with the Great Red Spot or getting pushed away when the two encounter each other in August, assuming their paths remain the same. The Little Red Spot lies at a lower latitude and will pass the Great Red Spot in June. Such changes in Jupiter's weather come as part of a global upheaval that began before the New Horizons spacecraft visited last year. The idea that Jupiter is undergoing global climate change was proposed in 2004 by Phil Marcus , a mechanical engineer at the University of California, Berkeley.

He predicted large changes in the southern hemisphere starting around 2006 that would destabilize jet streams and spawn new storms. Much of the activity in the gas giant's South Equatorial Belt has disappeared and left the Great Red Spot isolated, foreshadowing even greater changes to come. "The Great Red Spot may not always be the largest and strongest storm on Jupiter," said Glenn Orton, planetary scientist and study coauthor at NASA's Jet Propulsion Laboratory in Pasadena, Calif. Copyright ï¿½ 2008 Imaginova Corp. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed. Manuel Mitternacht May 25, 2008 Climate change ... the emergence of a second and third red spot on Jupiter suggest it's getting hot on the fifth planet. Hubble telescope Photo: Hubble Telescope JUPITER, the biggest planet of the solar system, famous for its big red spot and a newer second spot is growing a third. The Great Red Spot is a gas storm, three times the size of the planet Earth, that has raged for almost 350 years.

A second spot appeared in 2006 on the turbulent surface of the gas giant and could result from a temperature increase of up to 10 degrees in the equatorial region of the planet. New images from the space-based Hubble telescope, made public yesterday, reveal a new addition to Jupiter's storm-ravaged surface. A smaller storm, about half the size of Earth, has developed next to its giant neighbour and is estimated to collide with the big red spot in August. Astronomers expect a spectacular reaction when the two ferocious storms, spinning with wind speeds of up to 620 kilometres an hour, meet. University of California Berkeley scientist Michael Wong is looking forward to the encounter 750 million kilometres from Earth. "The small oval will either be absorbed or repelled from the Great Red Spot," he said. While turbulent storms on Jupiter are common, astronomers are puzzled about the nature of their red colour. A possible explanation is that only the powerful storms dredge materials from deep below the clouds to higher altitudes where ultraviolet radiation produces the dark red colour.

Source: The Sun-Herald Jupiter storm 'could become solar system's largest' Thursday, 22 May 2008 13:52 The Little Red Spot covers an area roughly the size of Earth and features winds of up to 384mph Jupiter is close to becoming the solar system's largest after scientists observed its size and wind speeds increasing. High resolution images of the Little Red Spot (LRS) have been combined with powerful Earth-orbital and ground-based imagery for the first time. The LRS is one of the largest and newest storms known to astronomers, with its age being dwarfed by its Jupiter neighbour the Great Red Spot (GRS), which has raged for more than three centuries. But as the GRS shrinks in terms of velocity and stature its smaller counterpart is showing signs of overtaking. Scientists say they have gained a greater understanding of LRS' future after combining data from Nasa's Pluto-bound New Horizons spacecraft, the Hubble Space Telescope and the European Southern Observatory's Very Large Telescope. The anticyclone covers an area roughly the size of Earth and features winds of up to 384mph, more than double a category five storm.

Dr Andrew Cheng of the John Hopkins University applied physics laboratory commented that the rapid changes observed at LRS remained one of the solar system's mysteries. "This unique set of observations is giving us hints about the storm's structure and makeup; from this, we expect to learn much more about how these large atmospheric disturbances form on worlds across the solar system," he explained. Jupiter Breaks Out in Spots By Space.com Staff posted: 23 May 2008 12:37 pm ET A third red spot has appeared on Jupiter in what astronomers called a case of the planetary measles. Astronomers spotted the new storm ï¿½ a distant smaller cousin of the Great Red Spot and Little Red Spot ï¿½ using the Hubble Space Telescope and W.M. Keck telescope to get both visible-light and near-infrared images. Turbulent storms are common in Jupiter's atmosphere, although the red color in the biggest storms remains a mystery. The new red spot, announced yesterday, was previously a white, oval-shaped storm.

One theory suggests such storms have enough power and size to dredge material from deep beneath Jupiter's clouds and lift it to higher altitudes, exposing it to solar ultraviolet radiation that changes the color to the now-familiar red. Early telescope observations indicate that the Great Red Spot has lasted somewhere between 200 and 350 years, while the Little Red Spot appeared in spring 2006. The third red spot was spotted in Hubble and Keck images taken between May 9 and May 11 of this year. The newest storm may end up merging with the Great Red Spot when the two meet in August, assuming they continue on their current paths, astronomers said. Otherwise the Great Red Spot may simply shove its smaller cousin aside. The latest Hubble and Keck images also support the idea of Jupiter undergoing global climate change. Warming near the giant planet's equator and cooling at the South Pole could be destabilizing the southern hemisphere, causing jet streams to go haywire and spawn new storms. posted: 04 May 2006 01:00 pm ET A storm is brewing half a billion miles away and in a rare event, astronomers get to watch it closely.

Jupiter is growing a new red spot and the Hubble Space Telescope is photographing the scene. Backyard astronomers have been following the action , too. "Red Spot Jr." as it is being called, formed after three white oval-shaped storms-two of which were at least 90 years old-merged between 1998 and 2000. A similar merger took place centuries ago and formed the bigger and legendary Great Red Spot, a storm twice as big as Earth and almost 300 years old. Close look Close inspections of Red Spot Jr., in Hubble images released today, reveal that similar to the Great Red Spot , the more recently developed storm rises above the top of the main cloud deck on Jupiter. Little is known about how storms form on the giant planet. They are often described as behaving similar to hurricanes on Earth. Some astronomers believe that the spots dredge up material deep below Jupiter's clouds and lift it to where the Sun's ultraviolet light chemically alters it to give it a red hue. The latest images could provide evidence that Jupiter is in the midst of a global change that can modify temperatures by as much as 10 degrees Fahrenheit on different parts of the globe.

The study was led jointly by Imke de Pater and Philip Marcus of University of California, Berkeley. "The storm is growing in altitude," de Pater said. "Before when they were just ovals they didn't stick out above the clouds. Now they are rising." This growth signals a temperature increase in that region, she said. Marking change The global change cycle began when the last of the white oval-shaped storms formed south of the Great Red Spot in 1939. As the storms started to merge between 1998 and 2000, the mixing of heat began to slow down at that latitude and has continued slowing ever since. The movement of heat from the equator to Jupiter's south pole is expected to stop at 34 degrees southern latitude, where Red Spot Jr. is forming. This will create a big wall and stop the mixing of heat and airflow, the thinking goes. As a result, areas around the equator become warmer, while the poles can start to cool down. Will Galileo Make Jupiter a Star?

September 14, 2003 Update (November 14, 2003): It turns out that I made an error in one of my arguments on the original version of this page. It doesn't affect the end result (that Galileo cannot blow up like a bomb), but I want to make sure I am honest here. I don't want this to get in the way of the main point, so I am putting the explanation of my error at the bottom of this page . This page now reflects the current arguments. Here is the old, incorrect page . In October of 1989, NASA launched the Galileo spacecraft toward the planet Jupiter. Its mission was manyfold: to explore the moons of the giant planet, to investigate the environment of Jupiter's neighborhood, and to drop a probe into Jupiter's atmosphere to measure its physical characteristics. After nearly eight years, Galileo's mission is over. It is out of fuel, and has been hammered by Jupiter's radioactive magnetic field for so long that its hardware is dying. NASA decided that the best thing to do is use the remaining fuel to drop the spacecraft into Jupiter, where it will burn up harmlessly.

They feel this is better than letting it continue to orbit the planet, because it might eventually crash into one of the moons. One such moon, Europa, may just possibly have the right conditions for life to evolve, and they don't want Galileo to contaminate the moon, even given the extremely long odds of it happening. Galileo will plunge into Jupiter on September 21, 2003, around 20:00 hours Greenwich time. But some people think that NASA had more plans for Galileo. They claim that NASA's nefarious scheme was to drop Galileo into Jupiter and use it to ignite Jupiter like a fusion bomb, either turning it into a star like the Sun, or simply blowing it to smithereens. J.C. Goliathan, one of the main proponents of this "Jupiter ignition" idea , has a long page about all this. Can this be true? Could NASA accomplish such a dastardly plot? As always, the short answer to this is to look at the title bar of your browser and read the name of this website. To save you time, I'll just say it here: no, Galileo will not do anything to Jupiter.

Like a meteor, it'll burn up in the dense atmosphere, and become a part of the solar system's largest planet. Yet the idea that Jupiter may explode is spreading across the web, sticking in this case (unlike the Moon Hoax or Planet X) mostly to the woowoo sites. So what are the main ideas behind it, and why are they wrong? There are several ideas put forth, and they are wrong for lots of reasons. They sound legitimate, as many pseudoscientific ideas do, but that's different than actually being right. Let's take a look. Here are the claims made by the alarmists: Galileo has plutonium onboard. This is what makes fission bombs! NASA plans on creating a fission bomb using Galileo. Fusion bombs are made by using fission bombs as triggers. The implosion caused by a fission bomb ignites hydrogen into fusion, generating a much bigger blast. Jupiter is made of mostly hydrogen! So it can be blown up like an H-bomb. Stars work by fusing hydrogen. Jupiter might turn into a star, or it might simply blow up like a bomb. Got all that? OK, point-by-point, let's see why it's all wrong.

1) Galileo has plutonium onboard. This is what makes fission bombs! NASA plans on creating a fission bomb using Galileo. Galileo does indeed have plutonium (Pu) onboard. The instruments onboard need power, and Jupiter is too far from the Sun to use solar power very well. The solar panels would need to be very large, too large and heavy to get to Jupiter. Instead, Galileo uses a tried-and-true technology: radioisotope thermoelectric generators (RTGs). Basically, these are extremely simple devices: inside an RTG is a pellet of radioactive material. As the material decays, it generates heat. The heat is converted to electricity, which powers the spacecraft. Galileo's RTGs use plutonium in the form of ceramic pellets of plutonium dioxide. There is about 50 pounds of Pu onboard, stored in 144 separate cylindrical pellets. There are two RTGs on Galileo, each with 72 pellets (a paper about RTGs with a diagram can be found at NASA's Space Science website) . Note: I am not going to get into a discussion over whether RTGs are safe, and the dangers or lack thereof posed by launching radioactive materials into space.

Please read Spaceviews' page on RTGs for more info, and their list of pro and anti RTG sites as well. Fission bombs work in this (simplified) way. The nucleus of a plutonium atom naturally splits into two or more pieces when a neutron (a subatomic particle) hits it. When it splits (also called fissioning), it releases energy and more neutrons. These hit other nuclei, causing them to split, etc. If the atoms are too far apart, then this effect won't work, because, basically, the neutrons miss the other nuclei. But if the atoms are packed tightly enough, you get a runaway reaction. More and more split, the energy released gets very big, and boom! Atomic bomb. The amount of mass you need packed together to get a runaway chain reaction is called the critical mass. For plutonium 238, the kind that was on Galileo, you need about 10 or so kilograms (22 pounds) all packed tightly into a ball. Galileo had more than that amount on board, but (and this is a huge but) it was spread out in smaller pieces.

The RTGs extend along a long boom, a rod that extends out from the main body of the spacecraft , and not in a way that works as a fission bomb. There are 72 separate chambers where the Pu238 was stored, and each piece had a sub-critical mass. You would have to compress those pieces together to make them critical and cause a fission reaction. But that could not happen. Why not? Because Galileo entered Jupiter at a speed of about 100,000 miles per hour. At that speed, the pressure would tear the spacecraft apart. It slows as it passes through denser atmosphere, of course, but the pressures would be so high at those velocities that Galileo would be shredded. As the pieces fall off, they are heated due to compressing the air in front of them. This is why meteors get hot, in fact, and at these speeds the metal on Galileo would melt in short order. This would release the plutonium, dispersing it. So instead of compressing it, as the pseudoscientists claim, the plutonium would actually get strewn through Jupiter, making it literally impossible to explode.

So step one -- Galileo becoming a fission bomb -- cannot happen. Not that this stops the pseudoscientists, of course. The doomcriers at YOWUSA make a big deal of how Pu is used in a bomb, and even show the geometry of a fission-induced fusion bomb (Note added November, 2003: YOWUSA has made their archives available only to subscribers, so the image is no longer available). But that's not how the RTGs are constructed! Posting that image is grossly misleading. The RTGs are not in anything like the geometry of a fission bomb. This is more obfuscation on the part of the doomsayers. Also, the YOWUSA folks, when quoting Goliathan , appear to think that somehow the pressure from the passage of Galileo through Jupiter's atmosphere will compress the plutonium enough to start a chain reaction, which will then trigger fusion. But the fission has to happen with precise timing, and in a certain geometry. How do they propose that will happen, exactly, with Galileo tumbling down into Jupiter, parts of it flying off due to the heat and pressure of supersonic atmospheric entry? They somehow conveniently left that part off of their description.

Conclusion: The plutonium on Galileo cannot fission to become a bomb. 2) Fusion bombs are made by using fission bombs as triggers. The implosion caused by a fission bomb ignites hydrogen into fusion, generating a much bigger blast. A hydrogen bomb explodes because atomic nuclei of hydrogen are squeezed together. If squeezed hard enough, the atomic nuclei fuse (stick together), and that releases energy. You have to apply a lot of pressure and heat to get the hydrogen to do this, and one way to do that is to use the blast wave from a fission bomb. Basically, a fission bomb is used to trigger a process which creates the hydrogen fuel for the fusion reaction (more on this in a moment). The shock wave and heat from the fission explosion must work in a very specific way to do this. When it works, the fusion releases far more energy than a fission explosion, which is why H-bombs have so much more explosive yield than A-bombs. And hey, isn't Jupiter mostly hydrogen? Yikes, a fission explosion can make Jupiter explode like a bomb! No, it can't, and for two reasons.

Well, three if you include the fact that Galileo couldn't make a fission bomb, as noted above. But even if it could, it wouldn't make Jupiter detonate, because the RTGs aren't configured to be used as a fission trigger, and because Jupiter doesn't have the right stuff in it to fuse. While Jupiter is mostly hydrogen, it's the wrong kind. Remember isotopes; atoms with different number of neutrons? Hydrogen has them too. A hydrogen nucleus at its simplest is just a lone proton. Deuterium (D2) is hydrogen with a neutron and a proton, and tritium (T3) is a proton with two neutrons. Fusion bombs need the neutron-added isotopes . Regular old hydrogen won't do it. Simply taking a sample of hydrogen gas and compressing it won't make it fuse; you need a fuel enriched with D2 and T3. Finding these materials isn't all that easy, and a randomly selected pocket of Jupiter's gas is unlikely in the extreme to have them in sufficient quantities to explode. What's worse, the way we make bombs these days, you need lithium to make them work, and that's not terribly common in Jupiter either.

Here's how a fusion bomb works. You need a fission explosion to start with, which is used to do two things: it generates X-rays, which heat and compress the fusion fuel, and it actually helps create the fuel. As I have discovered while researching this article, the process is somewhat complicated . In a very brief nutshell, the fission explosion is used to irradiate lithium. Neutrons from the fission explosion combine with the lithium to create tritium. The heat and pressure from the X-rays compress the tritium, and bang! Again, this sequence of events is highly unlikely to occur on Jupiter. You need lots of lithium, which is not terribly abundant. You need it to make tritium, which is highly unstable (it doesn't last long once created) and again unlikely in the extreme to be found in Jupiter's atmosphere. It's really just plain old silly to think this could happen with Galileo, even if it had the right kind of fission material. Which it doesn't. This doesn't stop Goliathan from speculating wildly, though. He says: However, conventional belief says that Deuterium and Tritium (isotopes of Hydrogen) are necessary to accomplish fusion.

Both may be present or created during a reaction within the dense liquid hydrogen of Jupiter. Again, he doesn't state how this might happen. I am not an expert on such things, and won't speculate, but it seems unlikely that Jupiter can create these elements, given that it takes nuclear reactions to do it (specifically, a proton has to absorb an electron and an anti-neutrino to become a neutron). Jupiter isn't big enough to do it. Even if you supplied a fission bomb, you won't get hydrogen (tritium) to fuse. And Galileo doesn't have what it takes to make a fission explosion. FROM: 3) Stars work by fusing hydrogen. Jupiter might turn into a star, or it might simply blow up like a bomb. OK, so we don't have fission, and we don't have fusion. So let's suppose, contrary to all evidence, that NASA is really lying to us, and has put fission bombs and fusion fuel aboard Galileo. When they go off, will Jupiter explode, or turn into a star? Nope, and nope. Fusion is not a runaway process.

Once you start it up, it generates a lot of heat, which tends to expand the material violently (this is what we technically call a bomb). This means the fuel gets scattered, and it won't fuse. Making really big hydrogen bombs run into this problem, making it hard to make really big bombs, which in my book is perhaps a good thing. So the process tends to damp itself off. Jupiter won't explode. It won't turn into a star, either. Stars work by maintaining fusion in their cores. Now, I just said fusion isn't self-sustaining, so how do stars keep it going? They do it by containing the hydrogen in a small volume. This is accomplished by piling a lot of mass on top of the hydrogen: the mass of the star. The star has enough gravity that all that mass squeezes and heats the core enough for fusion to not only take place, but to continue at a relatively stable pace. But it turns out there is a lower limit to that mass; if you don't have enough, then you don't get the high temperatures and pressures necessary to ignite fusion. That mass is about 0.077 times the mass of the Sun , or 80 times Jupiter's mass.

In other words, Jupiter is 1/80th the mass it needs to turn into a star. Some people call Jupiter a failed star , but in reality it ain't even close. Conclusion: Jupiter won't explode, or turn into a star, because it lacks the containment to keep fusion going. There's more, of course. Goliathan, in his article, makes lots of statements as if they are facts, but are actually wrong. For example, it might be relevant to ask why NASA doesn't simply boost Galileo out of the Jupiter system and into space, rather than smack it into Jupiter. Goliathan takes that farther: Some argue that the craft is caught in Jupiter's pull now, but with all of the gravity assist tricks available, and still some propellant left, the craft should be able to break free even if they had to use an assist of one of the larger moons. Here he shows a profound ignorance of the situation. Jupiter's gravity is immense. Escape velocity is quite high, nearly 6 times ( * ) that of Earth's! If Galileo had enough fuel to escape from Jupiter, then we wouldn't have needed to use gravity assists from Venus and twice with Earth .

As an example, the propellant used to get to Jupiter needed to change Galileo's velocity by about 15 kilometers/second (the difference between the Earth's orbital speed and Jupiter's). The rocket could not provide that on its own, so we needed help from the gravity of Venus and Earth. But, to escape Jupiter from, say, the distance of Europa, Galileo needs to add 6 km/s to its velocity, a healthy chunk of what it needed to get to Jupiter in the first place. Closer in to Jupiter the situation is even worse. Up until about 2001, there was enough fuel on board Galileo to have it get into an escape trajectory, but after that there was too little fuel left. If I have time I will add to this article over the next few days, but I think I've made it pretty clear that this idea that Galileo will somehow cause a nuclear explosion on Jupiter is wrong. Remember, if you hear something on the web about how some astronomical event may cause doomsday here on Earth, read it with a very skeptical eye. And check Bad Astronomy before you start putting your affairs in order! Richard A.

Kerr Planetary scientists hoped that the free-flying probe released into Jupiter's atmosphere by the spacecraft Galileo would return results they could use to help understand the formation of the gas giant and of the whole solar system. But thanks to a piece of bad luck, the probe came down in an uncharacteristically hot, dry, and cloudless spot--essentially a Jovian Sahara--dashing those hopes at least for now. Still, the data are offering new insights into Jupiter's weather, possibly helping resolve a debate about the origins of the planet's strong winds. On 1994 July 16-22, over twenty fragments of comet Shoemaker-Levy 9 collided with the planet Jupiter. The comet, discovered the previous year by astronomers Carolyn and Eugene Shoemaker and David Levy, was observed by astronomers at hundreds of observatories around the world as it crashed into Jupiter's southern hemisphere. This Web site is here to provide some of the images taken by amateur and professional astronomers before, during, and after the events, and to provide more information on this historic event.

Jupiter Facts: Interesting Facts about Planet Jupiter • The Planets Interactive Solar System Model Jupiter Facts Named after the Roman king of the gods, Jupiter is fitting of its name. With a mass of 1.90 x 1027 kg and a mean diameter of 139,822 km, Jupiter is easily the largest and most massive planet in the Solar System . To put this in perspective, it would take 11 Earths lined up next to each other to stretch from one side of Jupiter to the other and it would take 317 Earths to equal the mass of Jupiter. Size of Jupiter compared to the Earth Side by side comparison of the size of Jupiter vs Earth Moons of Jupiter Jupiter has 67 confirmed moons orbiting the planet. These moons are separated into three groups: Inner moons. These orbit the closest to Jupiter and are sometimes called the Amalthea group. The names of the inner moons of Jupiter are Metis, Adrastea, Amalthea, and Thebe. Galilean moons. These are largest of Jupiter’s moons and were discovered by Galileo Galilei in 1610 – Io, Europa, Ganymede and Callisto.

Outer moons. These moons are much smaller and further away from Jupiter. They also have irregular, elliptical orbit paths and many are captured asteroids. More information about the moons of Jupiter Facts about Jupiter The first recorded sighting of Jupiter were by the ancient Babylonians in around 7th or 8th BC. It is named for Jupiter, the king of the Roman gods and god of the Sky. The Greek equivalent is Zeus, god of thunder . For the Mesopotamians, he was the god Marduk and patron of the city of Babylon. Germanic tribes saw the planet as Donar, also known as Thor. When Galileo discovered the four moons of Jupiter in 1610 this was the first proof of celestial bodies orbiting something other than Earth. The discovery also provided further evidence of Copernicus’ Sun-centred solar system model. Jupiter has the shortest day of the eight planets. The planet rotates very Jupiter rotates very quickly, turning on its axis once every 9 hours and 55 minutes. This rapid rotation is also what causes the flattening effect of the planet, which is why it has an oblate shape. One orbit of the Sun takes Jupiter 11.86 Earth years.

This means that when viewed from Earth, the planet appears to move very slowly in the sky. It takes months for Jupiter to move from one constellation to the next. Jupiter has a faint ring system around it. Its ring is mostly comprised of dust particles from some of Jupiter’s moons during impacts from comets and asteroids. The ring system begins about 92,000 km above Jupiter’s clouds and reaches more than 225,000 km from the planet. The rings are somewhere between 2,000-12,500 km thick. Jupiter has at least 67 moons in satellite around the planet. This includes the four large moons called the Galilean moons that were first discovered by Galileo Galilei in 1610. The largest of Jupiter’s moons, Ganymede is the largest moon in the solar system. The moons are sometimes called the Jovian satellites and the largest of them are Ganymede , Callisto , Io and Europa . Ganymede is larger than the planet Mercury with a diameter of around 5,268 km. Jupiter has a very strong magnetic field.

This is around 14 times stronger than the magnetic field found on Earth – the largest of any planet in the solar system. Jupiter is the fourth brightest object in our solar system. After the Sun, the Moon and Venus, Jupiter is the brightest and is one of five planets which can be seen by naked eye from Earth. Jupiter is the only planet that has a center of mass with the Sun that lies outside the volume of the Sun, though by only 7% of the Sun’s radius. Jupiter has a very unique cloud layer. The upper atmosphere of the planet is divided into zones and cloud belts which are made of ammonia crystals, sulfur and a mixture of these two compounds. Eight spacecraft have visited Jupiter so far. Those are Pioneer 10 and 11, Voyager 1 and 2, Galileo, Cassini, Ulysses and the New Horizons mission. Another mission, Juno, is set to arrive at Jupiter some time around July 2016. There are also plans for future missions to focus on the Jovian moons of Jupiter – Europa, Ganymede and Callisto – and their possible subsurface oceans. Jupiter does not experience seasons like other planets such as Earth and Mars.

This is because the axis is only tilted by 3.13 degrees. Jupiter’s Great Red Spot is an enormous storm that has been raging for over 300 years. This storm is so wide that three Earth’s would fit inside of it. If Jupiter had become 80 times more massive, nuclear fusion would have occurred in its core. Had that happened, it would have become a star instead of a planet. More information and facts about Jupiter What is even more provocative is the theory that Jupiter is a failed star. Current scientific knowledge suggests that if Jupiter had, in fact, been roughly 80 times more massive, nuclear fusion would have taken place in its core; thus, Jupiter would have become a star, not a planet. Regardless, it is still tempting to look at the number of satellites orbiting Jupiter and consider it and its moons as, in many ways, a mini solar system. Although our scientific knowledge of Jupiter has been greatly expanded as a result of the numerous planetary missions beginning in the 1970s, these missions are unnecessary for viewing the planet’s surface features. Instead, most of these features can be observed using Earth-based telescopes.

For example, as recently as 1994, the Hubble Space Telescope provided stunning images of the impact of the Shoemaker-Levy 9 comet into Jupiter. Atmosphere The vertical dimension (i.e., thickness) of Jupiter’s atmosphere is more difficult to define than those of the terrestrial planets. For example, whereas the lower boundary for the atmosphere on Earth is its solid planetary surface, there is no such equivalent on Jupiter. Essentially, Jupiter’s atmosphere transitions from a gaseous outer zone into the planet’s liquid layer. However, for practical purposes scientists have designated the depth at which the atmospheric pressure equals ten times the pressure at sea level on Earth as Jupiter’s “surface”. Those layers of the atmosphere visible to Earth-based telescopes are divided into lighter and darker horizontal bands. Scientists believe these bands to be layers of high and low pressure. As a result, storms often develop on the boundaries between two adjacent bands. The Great Red Spot, visible in Jupiter’s southern hemisphere, is one such storm. Amazingly, this storm has raged for centuries and is 25,000 km across&#8212that is big enough to hold two Earths! The composition of Jupiter’s atmosphere is very interesting.

At roughly 90% hydrogen and 10% helium, Jupiter’s composition is nearly the same as the Sun’s. The only difference between the two is that the Sun is much more massive than Jupiter. This composition supports the theory that Jupiter could have been a star. Interior The interior of Jupiter is believed to consist of three regions. The first is a rocky core composed of various elements with a mass between 12 and 45 times that of the entire Earth . The core is surrounded by the second region, a layer of electrically conductive liquid hydrogen. It is due to this layer, which comprises most of the planet’s mass, that Jupiter has such a strong magnetic field. The third region consists of ordinary hydrogen with traces of helium, which transitions into the planet’s atmosphere. A fascinating property of Jupiter is that it emits more energy than it receives from the Sun. This is due to the planet being so massive. As a result of such a large mass, Jupiter exerts a strong gravitational force on itself, thus resulting in the compression of the planet as a whole. The cumulative effect of all this inward force is the production of a large amount of heat, which is then radiated into space.

Orbit & Rotation With a mean orbital distance of 7.78 x 108 km, Jupiter is, on average, a little more than five times the distance from the Earth to the Sun. This means that it takes about 43 minutes for sunlight to reach Jupiter. Also, Jupiter’s orbital eccentricity of .04838 is fourth largest among the planets, giving it a perihelion of 7.41 x 108 km and an aphelion of 8.16 x 108 km. Jupiter’s year is about 4,333 Earth days in length&#8212 that’s about 12 times the length of one Earth year! Jupiter’s axial tilt of 3.17° is extremely small, second lowest in the Solar System behind Mercury . What this means is Jupiter doesn’t experience seasons at all. Two things stand out about Jupiter’s rotation. The first is its speed. At just under 10 hours, Jupiter has the shortest rotational period in the Solar System.

(Saturn is a close second at 10.7 hours.) This quick rotational speed causes the planet to bulge near its equator, making it less spherical than most of the other planets. The second stand-out characteristic of Jupiter’s rotation is that different parts rotate at different speeds. This is due to Jupiter’s not being a solid body. For example, the polar atmosphere rotates about 5 minutes more slowly than that found at the equator. Rings Although the rings of Saturn are well-known, it is uncommon to hear anything about Jupiter’s rings. Nevertheless, Jupiter does have a ring system. Jupiter’s rings are lesser known than Saturn’s (or even Uranus ‘) because they are primarily composed of dust, which makes them difficult to see. The formation of these rings is believed to have come about through Jupiter’s gravity having captured material ejected from its moons. Jupiter Profile Why Jupiter's Great Red Spot Has Lasted So Long Why Jupiter's Great Red Spot Has Lasted So Long by Charles Q. Choi, SPACE.com Contributor Close-up of Jupiter's Great Red Spot as seen by a Voyager spacecraft.

More The mystery of why Jupiter's Great Red Spot did not vanish centuries ago may now be solved, and the findings could help reveal more clues about the vortices in Earth's oceans and the nurseries of stars and planets, researchers say. The Great Red Spot is the most noticeable feature on Jupiter's surface — a storm about 12,400 miles (20,000 kilometers) long and 7,500 miles (12,000 km) wide, about two to three times larger than Earth. Winds at its oval edges can reach up to 425 mph (680 km/h). This giant storm was first recorded in 1831 but may have first been discovered in 1665. "Based on current theories, the Great Red Spot should have disappeared after several decades," researcher Pedram Hassanzadeh, a geophysical fluid dynamicist at Harvard University,said in a statement. "Instead, it has been there for hundreds of years." [ Photos: Most Powerful Storms in the Solar System ] Vortices like the Great Red Spot can dissipate because of many factors. For instance, waves and turbulence in and around the storm sap its winds of energy.

It also loses energy by radiating heat. Moreover, the Great Red Spot rests between two powerful jet streams in Jupiter's atmosphere that flow in opposite directions and may slow down its spinning. Some researchers suggest that large vortices such as the Great Red Spot gain energy and survive by absorbing smaller vortices . However, "this does not happen often enough to explain the Red Spot's longevity," researcher Philip Marcus, a fluid dynamicist and planetary scientist at the University of California, Berkeley,said in a statement. The Great Red Spot is not the only mysterious vortex. In fact, vortices in general, including ones in Earth's oceans and atmosphere, often live much longer than current theories can explain. To help solve the mystery of the Great Red Spot's endurance, Hassanzadeh and Marcus developed a new 3D, high-resolution computer model of large vortices. Models of vortices generally focus on swirling horizontal winds, where most of the energy resides. Although vortices also have vertical flows, these have much less energy. Therefore, "in the past, most researchers either ignored the vertical flow because they thought it was not important, or they used simpler equations because it was so difficult to model," Hassanzadeh said.

The researchers now find that vertical flows hold the key to the Great Red Spot's longevity: When the storm loses energy, vertical flows move hot and cold gases in and out of the storm, restoring part of the vortex's energy. Their model also predicts radial flows that suck winds from the high-speed jet streams around the Great Red Spot toward the storm's center, helping it last longer. Together, vortices — whether on Jupiter or in Earth's oceans — may decay up to 100 times slower than researchers previously thought. "Some vortices in the oceans have been observed to last for several years and are believed to play an important role in the oceanic ecosystem and ocean-atmosphere interaction," Marcustold SPACE.com. In addition, "vortices with physics very similar to the Great Red Spot are believed to contribute to star and planet formation processes, which would require them to last for several million years. Both oceanic and astrophysical vortices are subjected to dissipating processes, and the mechanism described here for the longevity of the Great Red Spot presents a very plausible explanation for their longevity as well." The scientists caution that their model does not entirely explain the Great Red Spot's long life span.

They suggest that occasional mergers with smaller vortices may help prolong the giant storm's life as well, and have begun modifying their computer model to test this idea. In addition, their "current model does not account for compressibility of the flow or sphericity of the planet," Hassanzadeh told SPACE.com. "Although we believe that these effects do not change the conclusions of our work, we are planning to modify our model in the next step and include these effects." The scientists will detail their findings Nov. 25 at the annual meeting of the American Physical Society's Division of Fluid Dynamics in Pittsburgh. Jupiter's Great Red Spot is Shrinking | Science Mission Directorate May 15, 2014 Jupiter's Great Red Spot is Shrinking May 15, 2014: Jupiter's trademark Great Red Spot -- a swirling anti-cyclonic storm larger than Earth -- has shrunk to its smallest size ever measured. According to Amy Simon of NASA's Goddard Space Flight Center in Greenbelt, Maryland, recent NASA Hubble Space Telescope observations confirm the Great Red Spot now is approximately 10,250 miles across, less than half the size of some historical measurements.

Astronomers have followed this downsizing since the 1930s. Images of Jupiter's Great Red Spot taken by the Hubble Space Telescope over a span of 20 years show that the Great Red Spot is shrinking. Historic observations as far back as the late 1800s gauged the storm to be as large as 25,500 miles on its long axis. NASA Voyager 1 and Voyager 2 flybys of Jupiter in 1979 measured it to be 14,500 miles across. In 1995, a Hubble photo showed the long axis of the spot at an estimated 13,020 miles across. And in a 2009 photo, it was measured at 11,130 miles across. Beginning in 2012, amateur observations revealed a noticeable increase in the rate at which the spot is shrinking -- by 580 miles per year -- changing its shape from an oval to a circle. "In our new observations it is apparent very small eddies are feeding into the storm," said Simon.

"We hypothesized these may be responsible for the accelerated change by altering the internal dynamics and energy of the Great Red Spot." Simon's team plans to study the motions of the small eddies and the internal dynamics of the storm to determine whether these eddies can feed or sap momentum entering the upwelling vortex, resulting in this yet unexplained shrinkage. NASA's Juno spacecraft is hurtling toward Jupiter now, due to reach the giant planet in July 2016. Point-blank examination by Juno's instruments will undoubtedly help unravel the mystery. Stay tuned for updates from both Hubble and Juno . The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. Goddard Space Flight Center manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington.

Top Stories Spitzer and Kepler detect Jupiter-like storm on small star Spitzer and Kepler detect Jupiter-like storm on small star December 10, 2015 This illustration shows a cool star, called W1906+40, marked by a raging storm near one of its poles. Credit: NASA/JPL-Caltech Astronomers have discovered what appears to be a tiny star with a giant, cloudy storm, using data from NASA's Spitzer and Kepler space telescopes. The dark storm is akin to Jupiter's Great Red Spot: a persistent, raging storm larger than Earth. "The star is the size of Jupiter, and its storm is the size of Jupiter's Great Red Spot," said John Gizis of the University of Delaware, Newark. "We know this newfound storm has lasted at least two years, and probably longer." Gizis is the lead author of a new study appearing in The Astrophysical Journal. While planets have been known to have cloudy storms, this is the best evidence yet for a star that has one. The star, referred to as W1906+40, belongs to a thermally cool class of objects called L-dwarfs.

Some L-dwarfs are considered stars because they fuse atoms and generate light, as our sun does, while others, called brown dwarfs , are known as "failed stars" for their lack of atomic fusion. The L-dwarf in the study, W1906+40, is thought to be a star based on estimates of its age (the older the L-dwarf, the more likely it is a star). Its temperature is about 3,500 degrees Fahrenheit (2,200 Kelvin). That may sound scorching hot, but as far as stars go, it is relatively cool. Cool enough, in fact, for clouds to form in its atmosphere. "The L-dwarf's clouds are made of tiny minerals," said Gizis. Spitzer has observed other cloudy brown dwarfs before, finding evidence for short-lived storms lasting hours and perhaps days. In the new study, the astronomers were able to study changes in the atmosphere of W1906+40 for two years. The L-dwarf had initially been discovered by NASA's Wide-field Infrared Survey Explorer in 2011.

Later, Gizis and his team realized that this object happened to be located in the same area of the sky where NASA's Kepler mission had been staring at stars for years to hunt for planets. Kepler identifies planets by looking for dips in starlight as planets pass in front of their stars. In this case, astronomers knew observed dips in starlight weren't coming from planets, but they thought they might be looking at a star spot—which, like our sun's "sunspots," are a result of concentrated magnetic fields. Star spots would also cause dips in starlight as they rotate around the star. Follow-up observations with Spitzer, which detects infrared light, revealed that the dark patch was not a magnetic star spot but a colossal, cloudy storm with a diameter that could hold three Earths. The storm rotates around the star about every 9 hours. Spitzer's infrared measurements at two infrared wavelengths probed different layers of the atmosphere and, together with the Kepler visible-light data, helped reveal the presence of the storm. While this storm looks different when viewed at various wavelengths, astronomers say that if we could somehow travel there in a starship, it would look like a dark mark near the polar top of the star.

The researchers plan to look for other stormy stars and brown dwarfs using Spitzer and Kepler in the future. "We don't know if this kind of star storm is unique or common, and we don't why it persists for so long," said Gizis. Great Red Spot | Mission Juno Looks like you're using an older browser. For the best experience possible, please upgrade your browser or download a modern browser. We recommend these free browsers: Firefox or Chrome You must update your Flash version to view videos. For the optimal Juno experience please install Chrome. Download Chrome . Or continue to explore features of the Juno spacecraft using the links on your left. Great Red Spot Perhaps Jupiter’s most iconic feature is its Great Red Spot. A gigantic storm twice as big as Earth , the spot was first observed 300 years ago – and may have been churning long before that. Like a hurricane on Earth, the center is relatively calm, but farther out, the winds scream at 430 to 680 kilometers per hour (270 to 425 miles per hour). WIDER THAN OUR ENTIRE PLANET.

The spot, whose main cloud layer is likely ammonia , appears to be an area of upwelling, in which clouds billow up from below. We’re still unsure as to the exact chemistry responsible for the spot’s brick-red color, as many Jovian storms boast a similar shade. Some other storms are white, however. On Earth, hurricanes grow over oceans and dissipate soon after making landfall. But because Jupiter lacks a surface that slows or confines storms, Jovian winds and hurricanes last for centuries – if not longer. Sometimes Jupiter’s storms merge, combining to form even larger oval features. Bigger storms like the Great Red Spot gobble up smaller neighbors. Although calling features like the spot “storms” is an accurate way to describe them, they are technically termed anticyclones (cyclones whirl in the other direction). For scientists, a “storm” usually refers to turbulent updrafts of material, which appear less frequently and produce lightning. See how storms on Earth compare to Great Red Spot. Category 5 Hurricane on Earth SIZE Click to find out how many Earths can fit inside the Great Red Spot The Great Red Spot is ~3 times the size of Earth. d close What is the Great Red Spot?

What is the Great Red Spot? This browser doesn't support video. Download: What is the Biggest Planet in the Solar System? - Universe Today Universe Today What is the Biggest Planet in the Solar System? Article Updated: 23 Dec , 2015 by Matt Williams Ever since the invention of the telescope four hundred years ago, astronomers have been fascinated by the gas giant of Jupiter. Between it’s constant, swirling clouds, its many, many moons, and its Giant Red Spot, there are many things about this planet that are both delightful and fascinating. But perhaps the most impressive feature about Jupiter is its sheer size. In terms of mass, volume, and surface area, Jupiter is the biggest planet in our Solar System by a wide margin. But just what makes Jupiter so massive, and what else do we know about it? Size and Mass: Jupiter’s mass, volume, surface area and mean circumference are 1.8981 x 1027 kg, 1.43128 x 1015 km3, 6.1419 x 1010 km2, and 4.39264 x 105 km respectively.

To put that in perspective, Jupiter diameter is roughly 11 times that of Earth, and 2.5 the mass of all the other planets in the Solar System combined. But, being a gas giant, Jupiter has a relatively low density – 1.326 g/cm3 – which is less than one quarter of Earth’s. This means that while Jupiter’s volume is equivalent to about 1,321 Earths, it is only 318 times as massive. The low density is one way scientists are able to determine that it is made mostly of gases, though the debate still rages on what exists at its core (see below). Composition: Jupiter is composed primarily of gaseous and liquid matter. It is the largest of the gas giants, and like them, is divided between a gaseous outer atmosphere and an interior that is made up of denser materials. It’s upper atmosphere is composed of about 88–92% hydrogen and 8–12% helium by percent volume of gas molecules, and approx. 75% hydrogen and 24% helium by mass, with the remaining one percent consisting of other elements.

This cut-away illustrates a model of the interior of Jupiter, with a rocky core overlaid by a deep layer of liquid metallic hydrogen. Credit: Kelvinsong/Wikimedia Commons The atmosphere contains trace amounts of methane, water vapor, ammonia, and silicon-based compounds as well as trace amounts of benzene and other hydrocarbons. There are also traces of carbon, ethane, hydrogen sulfide, neon, oxygen, phosphine, and sulfur. Crystals of frozen ammonia have also been observed in the outermost layer of the atmosphere. The interior contains denser materials, such that the distribution is roughly 71% hydrogen, 24% helium and 5% other elements by mass. It is believed that Jupiter’s core is a dense mix of elements – a surrounding layer of liquid metallic hydrogen with some helium, and an outer layer predominantly of molecular hydrogen. The core has also been described as rocky, but this remains unknown as well. In 1997, the existence of the core was suggested by gravitational measurements, indicating a mass of from 12 to 45 times the Earth’s mass, or roughly 4%–14% of the total mass of Jupiter.

The presence of a core is also supported by models of planetary formation that indicate how a rocky or icy core would have been necessary at some point in the planet’s history in order to collect its bulk of hydrogen and helium from the protosolar nebula. However, it is possible that this core has since shrunk due to convection currents of hot, liquid, metallic hydrogen mixing with the molten core. This core may even be absent now, but a detailed analysis is needed before this can be confirmed. The Juno mission , which launched in August 2011, is expected to provide some insight into these questions, and thereby make progress on the problem of the core. The temperature and pressure inside Jupiter increase steadily toward the core. At the “surface”, the pressure and temperature are believed to be 10 bars and 340 K (67 °C, 152 °F). At the “phase transition” region, where hydrogen becomes metallic, it is believed the temperature is 10,000 K (9,700 °C; 17,500 °F) and the pressure is 200 GPa.

The temperature at the core boundary is estimated to be 36,000 K (35,700 °C; 64,300 °F) and the interior pressure at roughly 3,000–4,500 GPa. Moons: The Jovian system currently includes 67 known moons. The four largest are known as the Galilean Moons , which are named after their discoverer, Galileo Galilei . They include: Io , the most volcanically active body in our Solar System; Europa , which is suspected of having a massive subsurface ocean; Ganymede , the largest moon in our Solar System; and Callisto , which is also thought to have a subsurface ocean and features some of the oldest surface material in the Solar System. Then there’s the Inner Group (or Amalthea group), which is made up of four small moons that have diameters of less than 200 km, orbit at radii less than 200,000 km, and have orbital inclinations of less than half a degree. This groups includes the moons of Metis , Adrastea , Amalthea , and Thebe .

Along with a number of as-yet-unseen inner moonlets, these moons replenish and maintain Jupiter’s faint ring system. Jupiter also has an array of Irregular Satellites, which are substantially smaller and have more distant and eccentric orbits than the others. These moons are broken down into families that have similarities in orbit and composition, and are believed to be largely the result of collisions from large objects that were captured by Jupiter’s gravity. Illustration of Jupiter and the Galilean satellites. Credit: NASA Interesting Facts: Much like Earth, Jupiter experiences auroras near its northern and southern poles. But on Jupiter, the auroral activity is much more intense and rarely ever stops. The intense radiation, Jupiter’s magnetic field, and the abundance of material from Io’s volcanoes that react with Jupiter’s ionosphere creates a light show that is truly spectacular. Jupiter also has a violent atmosphere. Winds in the clouds can reach speeds of up to 620 kph (385 mph). Storms form within hours and can become thousands of km in diameter overnight. One storm, the Great Red Spot , has been raging since at least the late 1600s.

The storm has been shrinking and expanding throughout its history; but in 2012, it was suggested that the Giant Red Spot might eventually disappear . The discovery of exoplanets has revealed that planets can get even bigger than Jupiter. In fact, the number of “ Super Jupiters ” observed by the Kepler space probe (as well as ground-based telescopes) in the past few years has been staggering. In fact, as of 2015, more than 300 such planets have been identified. Notable examples include PSR B1620-26 b (Methuselah), which was the first super-Jupiter to be observed (in 2003). At 12.7 billion years of age, it is also the third oldest known planet in the universe. There’s also HD 80606 b (Niobe), which has the most eccentric orbit of any known planet, and 2M1207b (Lerna), which orbits the brown dwarf Fomalhaut b (Illion). Scientist theorize that a gas gain could get 15 times the size of Jupiter before it began deuterium fusion, making it a brown dwarf star.

Good thing too, since the last thing the Solar System needs if for Jupiter to go nova! Jupiter was appropriately named by the ancient Romans, who chose to name after the king of the Gods (Jupiter, or Jove). The more we have come to know and understand about this most-massive of Solar planets, the more deserving of this name it appears. If you’re wondering, here’s how big planets can get with a lot of mass, and here’s what is the biggest star in the Universe . And here’s the 2nd largest planet in the Solar System. Here’s another article about the which is the largest planet in the Solar System , and here’s what’s the smallest planet in the Solar System . We have recorded a whole series of podcasts about the Solar System at Astronomy Cast . Check them out here. Source:

Question: What feature of Jupiter is a storm that has lasted for centuries and has a bigger diameter than planet Earth?
Answer: Great Red Spot