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.
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.
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
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 © 2008 Imaginova Corp. All Rights Reserved. This material may not be published, broadcast, rewritten or redistributed.
Climate change ... the emergence of a second and third red spot
on Jupiter suggest it's getting hot on the fifth planet. Hubble
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.
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.
spotted the new storm — a distant smaller cousin of the
Great Red Spot and Little Red Spot — 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.
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.
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.
Hubble and Keck images also support the idea of Jupiter
undergoing global climate change. Warming near the giant
and cooling at the South Pole could be destabilizing the southern hemisphere, causing jet streams to go haywire and spawn new storms.
New Storm on Jupiter Hints at Climate Change
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
following the action,
"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 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
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
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.
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.
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
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.
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
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:
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
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
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
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
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
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
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
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.
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
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
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
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
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
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!
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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
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.
Calculations shortly after the discovery of Comet Shoemaker-Levy 9 in March 1993 showed that the comet was in orbit about Jupiter and would collide with the planet...
JUPITER DATABASE ON THIS SITE
JUPITER'S MOON CALISTO
JUPITER'S MOONS IO AND EUROPA