Slashdot Mirror


Jupiter's Great Dark Spot

Edball writes "For more than a century astronomers thought that the Great Red Spot was the biggest thing on Jupiter. Not anymore. Images from NASA's Cassini spacecraft have revealed something at least as large, The Great Dark Spot." In related solar system news, pajamacore writes "Space.com reports that the first extrasolar planet to have its atmosphere detected is having its gas envelope boiled off by heat and blown away by tidal forces. At present, the planet is 70% the size of Jupiter but its orbit is closer to its parent star than Mercury's is to our own Sun. It should be a treat to eventually see the planet's core and maybe it'll clue us in a bit to gas giant formation."

46 of 195 comments (clear)

  1. Oh My God! It's full of stars! by izto · · Score: 2, Insightful

    So I guess mankind may as well send a spaceship there and find out about the all-mighty monoliths preparing for sparking life in Europa.

    1. Re:Oh My God! It's full of stars! by Jason1729 · · Score: 2, Informative

      Didn't you hear about the radiation belt? The new theory is no life on Europa

      Jason
      ProfQuotes

    2. Re:Oh My God! It's full of stars! by umofomia · · Score: 4, Insightful
      Didn't you hear about the radiation belt? The new theory is no life on Europa
      I wouldn't be so quick to dismiss the possiblity of life on Europa. The fact is that there are types of organisms on Earth that thrive in a radiation-filled environment. On Earth, wherever there is liquid water, there is life, even under the most extreme circumstances. Underneath Europa's thick layer of ice, most evidence points to there being an ocean of liquid water, so I wouldn't be surprised if life is found there.
  2. Looks suspicious by MacroRex · · Score: 5, Funny

    Maybe it's just me, but the dark spot in the center of the animation looks very artificial. It's clearly six-sided until the very end of the animation. Maybe the poor astronomer was bored and just wanted to have some material published for a change, you know, have his fifteen minutes of fame. Or it's the aliens. Always the aliens, dammit.

    1. Re:Looks suspicious by delstar+dotstar · · Score: 2, Funny

      Finally having RTFA and learning that the black spot in the center is at J's North Pole, look south of it, not north. Hee.

    2. Re:Looks suspicious by Izmunuti · · Score: 2, Funny

      "I presume the black mark in the middle of the picture is an artifact of the imaging process."

      Not at all. Like Earth, Jupiter is hollow. The black spot is the polar entrance to the subjovian realm. The Earth has a similar hole at the North pole but the UN, with help from the Illuminati covered it up. In the near future NASA plans to crash Galileo into the Jovian hole in hopes of collapsing it.

      I learned all of this during my most recent abduction.

      Iz

    3. Re:Looks suspicious by NovaChild · · Score: 2, Informative

      I actually worked at the Jet Propulsion Laborotory with Dr. West this past summer. The hexagonal spot in the middle is a result of the fact that this is a polar view of Jupiter created by combining 6 frontal images of jupiter. That is, we took six pictures of the front of jupiter, ignored all but the top half, changed the coordinates about, and put them back together to get an approximation of the polar view for that day. Since none of the pictures could actually SHOW the north pole, the area around it is placed with black.

      The further from the pole you get, however, the more accurate the images, and where the dark spot is found the images are quite accurate.

      Too bad I didn't read this article sooner, as most people will never see this comment.

  3. Leave it alone... by Anonymous Coward · · Score: 5, Funny

    Jupiter's probably very sensitive about it.

  4. Dave? Is that you? by Anonymous Coward · · Score: 5, Funny

    They didn't happen to take a close up of it and discover a cloud of spinning blocks, size 1kmx4kmx9km, did they?

  5. Looks like ... by B3ryllium · · Score: 2, Funny

    Looks like someone forgot to wipe the lense properly

  6. It's too late! by molrak · · Score: 3, Funny

    The monoliths are already forming! Now we really need to stay away from Europa.

    Note to self: find someone get to work on that Bowman virus post-haste.

    --
    You're only as smart as your brain.
  7. Faster better cheaper? by Tailhook · · Score: 3, Interesting
    Chalk one up for slow, lame(?) and expensive. Cassini is firmly among the old-school "big budget" NASA projects. The probe cost over 3 billion dollars. Read about that here.

    Cassini. Remember that name. You're going to hear a lot about Cassini over the next few years. The knowledge brought to us by that probe will make science headlines for the rest of this decade. Not bad for something that cost 15% of the Federal Foodstamp budget in FY2001.

    --
    Maw! Fire up the karma burner!
    1. Re:Faster better cheaper? by Holger+Spielmann · · Score: 4, Insightful

      Not bad for something that cost 15% of the Federal Foodstamp budget in FY2001.

      Or only three days (<1%) of the current USA defense budget...

    2. Re:Faster better cheaper? by Tailhook · · Score: 3, Insightful
      Ah yes. The US military. Only 27% of the FY2004 budget after waging war in the Middle East. Another excellent bargain.

      Good point! Thanks. :)

      --
      Maw! Fire up the karma burner!
    3. Re:Faster better cheaper? by EvilTwinSkippy · · Score: 4, Interesting
      You're going to hear a lot about Cassini over the next few years.

      That is assuming the folks at Lockhead and Boeing can stick to metric.

      Man, if I screw up a client's computer, I don't get hired back. Hell, they will usually go so far as to tell their friends and peers not to use me.

      If you are a miliary^H^H^H^H^H^Haerospace contractor and you screw something up you get bonuses and additional contracts.

      --
      "Learning is not compulsory... neither is survival."
      --Dr.W.Edwards Deming
    4. Re:Faster better cheaper? by FTL · · Score: 4, Insightful
      > Chalk one up for slow, lame(?) and expensive. Cassini is firmly among the old-school "big budget" NASA projects. The probe cost over 3 billion dollars.

      Cassini is the last of the "billion dollar probes". Others in the series included Terra, Galileo, Magellan and Mars Observer. These probles are a legacy of the 80s. It was the astronomical cost of these probes that made NASA launch the "faster/better/cheaper" programs.

      Cassini predates F/B/C and is the end of an era. We won't see the likes of Cassini again in our life times.

      It's difficult to say which is better, a lot of F/B/C probes (think plastic disposable watches), or a single billion $ probe (think Rolex: takes a licking and keeps on ticking). I think there's room for both types.

      --
      Slashdot monitor for your Mozilla sidebar or Active Desktop.
    5. Re:Faster better cheaper? by kilonad · · Score: 2, Interesting

      You get additional contracts because who else are you going to hire? The number of large, experienced aerospace companies is tiny and for a while was shrinking every year with all the mergers. Imagine you bought a car from Ford, and you were unhappy with it. Now imagine your only other choices were GM/Chevy (the same company) or Chrysler/Dodge, and you had problems with both of those companies in the past. Who are you going to buy your next car from? You surely won't buy it from some shady guy who made it in his garage down the street. This is why the big aerospace companies keep getting contracts. On the whole, they've done a pretty good job with their contracts (or else they wouldn't be getting them), and if they haven't, they offer such a compelling product that the government is willing to take that risk.

  8. Somewhat unrelated... by 1fitz2many · · Score: 2, Interesting

    Today's APOD has a pic of Jupiter in IR (can't see the pole though).

  9. Another spot? by megazoid81 · · Score: 4, Funny

    When will astronomers find Jupiter's G-spot?

  10. Losing mass, changing orbit? by gnovos · · Score: 3, Interesting

    Wouldn't the loss of mass for that planet eventually cause it's orbit to get bigger and bigger? Eventually it would reach some kind of break even point where it's no bigger than the head of small dog, no?

    --
    "Your superior intellect is no match for our puny weapons!"
    1. Re:Losing mass, changing orbit? by drayzel · · Score: 4, Informative

      No the orbit would not get bigger and bigger. What force would act upon it? Another object with MORE gravitational force than the planets star would be needed. Mass being stripped off would affect the core though. It is often theorized that Jupiter has a rocky core 8 times the mass of the Earth, yet because of the emense pressure of the surrounding gases it is compresses it to a diameter of 11,000 KM, just smaller than the 12,800 KM diameter of the Earth. The estimated atmospheric pressure is near 70 million atmospheres with a tempature near 22,000 Kelvin. So as the gas is drawn away from the core it would expand and cool (because of a decreased Kelvin-Helmholtz effect). The heavy core would actualy look larger than it was in it's compressed form. This of course would take many many millions of years. I would specualte by that time we'd have discoverd other planets past that particular stage of life. I think a more interesting question would be as to WHY the atmosphere is being yanked by the star? It was thought that Jovian panets would only form at sufficient distances from a stars gravitaional force, otherwise all that Hydrogen and Helium would have been captured by the sun leaving a terrestial planet with a thinner atmosphere if any at all. Has the star expanded to a larger size or has the planet changed orbit? Another interesting factoid about Jupiter. The "Great Red Spot" was first detected in 1664 by Robert Hooke. Other similar but smaller and much more temporary storms are commonly seen. ~Z

    2. Re:Losing mass, changing orbit? by umofomia · · Score: 2, Informative
      Another interesting factoid about Jupiter. The "Great Red Spot" was first detected in 1664 by Robert Hooke.
      According to this, Giovanni Cassini discovered the Great Red Spot in 1655.
    3. Re:Losing mass, changing orbit? by Yunzil · · Score: 2, Insightful

      No the orbit would not get bigger and bigger. What force would act upon it?

      Yes it would, actually. The planet it doesn't need a force acting on it to pull it away. The point is that there is less force acting on it to keep it close in. The star and the planet orbit around a common center of mass. If either one of them loses mass, the radius of their orbits around the c.o.m. will get larger.

    4. Re:Losing mass, changing orbit? by doughmein_dot_net · · Score: 2, Interesting
      Yes, but when the planet "loses mass", where does that mass go?

      When it gets stripped away, either the solar wind will carry it away from the star, or it will remain in orbit around the star at roughly the same place. From the observations so far, it looks like the mass is staying in roughly the same place - in the orbital path of the planet, which causes it to behave like the "comet's tail" that it essentially is. Therefore, the star, its planet, AND its gas trail will be orbiting one common center of mass, and barring any effects by the solar wind, this should not change appreciably.

      Remember that this planet is maybe 7 million miles from its star, by which point it is so close that there would need to be a very major force from a 3rd party in order to remove any of its mass from that vicinity. The star exerts a very strong grip on that planet at that distance.

      However, the remainder of the mass of the planet remains gravitationally bound to the star. Remember that the star's gravitational field affects all mass according to the inverse-square law. Even though there will be less of a planet in one roughly spherical ball, and the dwindling planet will exert less total gravitational force on the star, the star will still exert the same gravitational force on the remaining planet and it will stay in orbit pretty much where it is.

      Actually, now that I think about it, the drag and tidal effects would probably take away the planet's orbital speed over time, which means that it would lose kinetic energy and drop even closer to its star as it dissipates.

      Your argument about "less force acting" is fallacious - it's the same force and it applies to all mass. According to your logic, blowing the dust off a dirty tabletop would mean the table starts to float away from the ground. Sorry, but gravity just doesn't work that way. Remember the classical "thought experiment" where a bowling ball and a feather are both dropped in a vacuum? Remember how they both ended up landing at the same time? Just because the bowling ball is shedding dust doesn't prevent it (or rather, its common center of mass) from hitting the ground at the same time as the feather. Gravity works equally across all mass according to the inverse square law. The fact that the bowling ball has more mass to start merely means that it exerts more force on the ground in return.

      --
      Super ninja monkeys will one day rule the world!
    5. Re:Losing mass, changing orbit? by lobsterGun · · Score: 2, Insightful

      I'm no astronomer, but wouldn't the force of attraction between Jupiter and the Sun be dependant on the masses sum of their masses. As the mass of Jupiter decreases it so would the force of attraction. As the force of attraction decreased wouldn't the orbit get larger?

      I have all of these question marks because I'm not sure how the reduction in mass would affect the momentum of the Jupiter. Lemme try to work this out before you answer me.

      The gravitational force between the Sun and Jupiter would be ((G * massSun * massJupiter)/ (orbit of Jupiter)^2).

      The momentum of Jupiter as it travels in its orbit would be (massJupiter * orbitalVJupiter).

      It seems to me that if the momentum of Jupiter exceeded the force of attraction between it and the Sun, Jupiter would just drift away. and if force of attraction between Jupiter and the Sun exceeded Jupiter's momentum it would be pulled into the Sun. Therefore it seems that the two forces must be equal.

      Since the mass of the Sun, the orbital velocity of Jupiter, and the distance between the two bodies is effectivly constant, reducing the mass of Jupiter should have equal affect on both the momentum and the force of attraction.

      So to answer my question: No. the orbit of Jupiter should not get any bigger.

      Did I miss anything?

  11. joke, right? by djupedal · · Score: 2, Insightful

    The image is artificial (composite of Cassini ultra-violet (UV) images)...and subject to artifacts. Squint and look to the left...that should soften it up just enough to make it look 'real'...

    c'mon...

  12. Re:Earth by EvilTwinSkippy · · Score: 3, Funny
    That isn't a dark spot - that's just a collection of the densest matter on Earth.

    (An oldie but goodie...)

    New York (AP) - The heaviest element known to science was recently discovered by researchers at the University of Fulchester. The element, tentatively named Administratium, has no protons or electrons and thus has an atomic number of 0. However, it does have 1 neutron, 125 assistant neutrons, 75 vice neutrons and 111 assistant vice neutrons. This gives it an atomic mass of 312. These 312 particles are held together by a force that involves the continuous exchange of meson-like particles called morons. Since it has no electrons, Administratium is inert. However, it can be detected chemically as it impedes every reaction it comes in contact with. According to the discoverers, a minute amount of Administratium caused one reaction to take over four days to complete when it would have normally occurred in less than one second. Administratium has a normal half-life of approximately three years, at which time it does not actually decay but instead undergoes a reorganisation in which assistant neutrons, vice neutrons and assistant vice neutrons exchange places. Some studies have shown that the atomic mass actually increases after each reorganisation. Research at other laboratories indicates that Administratium occurs naturally in the atmosphere. It tends to concentrate at certain points such as government agencies, large corporations and universities and can usually be found in the newest, best appointed and best maintained buildings. Scientists point out that Administratium is known to be toxic at any level of concentration and can easily destroy any productive reaction where it is allowed to accumulate. Attempts are being made to determine how Administratium can be controlled to prevent irreversible damage, but results to date are not promising.

    --
    "Learning is not compulsory... neither is survival."
    --Dr.W.Edwards Deming
  13. Uhm... by Anonymous Coward · · Score: 4, Funny

    when have astronomers *ever* found a G-spot?

    I kid, I kid ;)

  14. Re:...and it's radioactive! by Luyseyal · · Score: 2, Informative

    "Risked" is a strong word.

    • http://www.planetary.org/news/Cassini/hot-top-ca ssini3.html
    • http://www.nuclearspace.com/facts_about_rtg.htm
    • ... see google

    -l

    --
    Help cure AIDS, cancer, and more. Donate your unused computer time to worldcommunitygrid.org. Join Team Slashdot!
  15. Re:A moon hit the planet by Anonymous Coward · · Score: 5, Informative

    Yeah right. Learn some basic astronomy. Underneath the outer atmosphere is liquid metallic hydrogen. What does that mean? There is no true surface, and disturbance would quickly be smoothed over. Yes, many have theorized that there may be a small rocky core underneath it all, but it is insignificant compared to the the rest. I seriously doubt there'd be any surface features there, and even if there was, why would it reflect itself through such a dynamic atmosphere? I think not.

  16. Beside Europa by jsse · · Score: 4, Informative

    Don't forget there are two other moons have been known to have similar subterranean worlds. Very strong evidence has been discovered to support the idea of subterranean oceans beneath the surfaces of two other Galilean moons, Ganymede and Callisto. While these would be colder, there is also far less radiation to wory about. With some luck, any of these three worlds may well host life, weither microbial or maybe something more complex.

  17. Re:A moon hit the planet by Ilan+Volow · · Score: 2, Funny

    I bet that there must be a surface structure under those spots.

    Most likely it's a gigantic cloud city run by Billy Dee Williams.

    --
    Ergonomica Auctorita Illico!
  18. Re:I don't know how to take this... by 6hill · · Score: 5, Insightful
    I mean, space exploration is great, but so is making sure that everyone has food to eat.

    The piddling money we use on space exploration cannot even begin to solve the world's hunger problem. However, there's the odd chance the said space exploration will sometime in the future solve the world hunger problem (from results in zero-gravity growth experiments to terraforming). That slim chance is certainly better than that offered by e.g. our military. I doubt its enormous budget will in any way affect world hunger except negatively.

  19. Why combine the stories? by zero_offset · · Score: 2, Insightful
    I don't understand why the piece about the extrasolar planet losing its gas envelope was combined with this other piece about Jupiter. Is it just because they're both "pretty far away"?

    If I had been in more of a hurry, I would have completely missed the thing about the gas envelope, which I find very interesting and would have stopped to read, because I already knew about the dark spot on Jupiter and wouldn't have considered it worth my time.

    Were the two stories combined by the article submitter, or was this more weirdness from the /. editors?

    --

    Slashdot quality declines as the number of hot grits posts decreases. - Provolt's Law, Apr-09-2005

  20. Life on Jupiter? by nairolF · · Score: 4, Insightful

    Okay, so mod me down for offtopic, but one thing that has always bothered me is, why don't people seriously (i.e. besides science fiction) consider the possibility of life of some form inside a gas giant? Sure, there is no liquid water, hence probably no "life as we know it", but if there are other forms of life as we don't (yet) know it, wouldn't this be an even greater discovery?

    What is needed for life (of any reasonable definition) to evolve in an environment, is that arbitrarily complex structures can form in such an environment. Basically, the environment must be "interesting". Nothing ever happens on the surface of our moon, so we don't expect life to evolve there. On the other hand, all kinds of cool chemical reactions can occur in liquid water - as has happened here on Earth. But what about Jupiter's atmosphere? There certainly are interesting molecules floating about - in fact the "Great Dark Spot" is conjectured to be a cloud of hydrocarbon droplets. There is plenty of energy - kinetic (storms), electric, magnetic, some solar as well as plenty of radioactivity. What's more, the environment is HUGE. You have all ranges of pressure from near-vacuum to something ridiculously dense in the core, and everything in between. Is it possible for some region inside Jupiter to have what it takes for life to evolve? And, since there are other sources of energy besides solar, this might happen in the dark depth, where we will never find it. Maybe there's a whole civilization deep in there that we're not aware of.

    Does this remind anybody else of the Slylandros in StarControl 2?

    --
    "...Look on my works, ye mighty, and despair!"
    1. Re:Life on Jupiter? by BDew · · Score: 2, Informative

      The standard objection to this is convection. While there certainly are levels in Jupe's atmosphere where the temp and pressure could possibly sustain life as we know it, Jupe's atmosphere is incredibly turbulent in the radial direction. Anything in the "pleasant" zone would quickly be thrust up into the outer layers or sink into the crushing layers.

      That said, I wouldn't give up on life there either...

      --
      "Fifty million Americans can't be wrong," said Rep. Billy Tauzin. Gore - 50,999,897 Bush - 50,456,002
  21. Actually, they're completely wrong by xeeno · · Score: 3, Funny

    The biggest structure is the great great white non-spot that surrounds the great dark spot.

  22. Re:A moon hit the planet by Oddly_Drac · · Score: 3, Interesting

    "Learn some basic astronomy."

    You mean planetography.

    "Underneath the outer atmosphere is liquid metallic hydrogen. What does that mean?"

    You're putting forward theory as fact and missing a several thousand kilometre thick wodge of increasingly dense gas that can stay partially stable for months or centuries in the case of the Great Red Spot.

    OD

    --
    Oddly Draconis
    Too cynical to live, too stubborn to die.
  23. Role of Federal Gov't. by goldspider · · Score: 3, Insightful
    I know anything defending the military is modded down by default, but I feel I need to get this off my chest. And way to find such an objective source...

    Explain to me how spending money on the military is bad? What else is the federal government supposed to spend our taxes on??

    As far as I'm concerned, the government's 1 and only job is to protect us so that we can live our lives however we choose. It is not the federal government's job to compensate for poor financial planning. It's not the federal government's job to provide to take care of me when I won't take care of my self. It's not the federal government's job to take my hard-earned paycheck and give it to someone who probably hasn't earned it.

    So let me ask you again; what SHOULD our federal taxes fund? If it's anything more than protecting our freedom, it's none of the federal government's business.

    --
    "Ask not what your country can do for you." --John F. Kennedy
  24. Re:I don't know how to take this... by aallan · · Score: 4, Insightful

    Either Cassini is really expensive for an unmanned research probe or poor people are being neglected. I mean, space exploration is great, but so is making sure that everyone has food to eat.

    Look, we have enough money and food to feed everyone on the planet decently, we just don't choose to, or our governments don't choose to, or someboday somewhere has decided that we aren't going to...

    The money spent on the space program is a drop in the ocean, and has absolutely nothing to do with the fact there are still people starving to death in the 3rd world. If we aren't going to spend it on feeding people anyway (and lets face it, we aren't) better to spend it doing something to advance science and human knowledge than buying another couple of B-1B bombers, surely?

    Al.
    --
    The Daily ACK - Eclectic posts by yet another hacker
  25. Worst quote ever in the Space topic by teamhasnoi · · Score: 3, Funny
    Meanwhile, West would be delighted just to see the Dark Spot again. "It's elusive," he says. But he's ready to be blown away ... any time.

    Geez, write a personal or something...

  26. Re:I don't know how to take this... by Wyatt+Earp · · Score: 2, Interesting

    There is enough food for everyone to eat.

    There isn't enough infrastructure to move it around efficently.

    And in some cases the leadership of a nation will do things that cause starvation - Robert Mugabe

    Or sometimes it's a mix of the two, like in the DPRK, where food shipments wait on the docks until the Army can rebag the food so the people don't know it's from the US, RoK or Japan.

  27. Re:Role of Federal Gov't. - Going a bit OT here by kilonad · · Score: 5, Insightful
    Spending money on the military is fine, up to a point. When you're spending money on R&D and creating jobs, that's just fine. When you're about to spend half a billion dollars on cruise missiles alone that you'll never get back, that's not as good. Sure, people had to be employed to make those bombs, but what happens when the war is over and they aren't needed anymore? And when all the soldiers come back and look for jobs in the private sector, having fulfilled their military duties? Another flood of unemployment, bad for the economy.

    The government has more jobs than just protecting us. Even so, "protection" is a very vague concept that entails more than just having a strong military. We the people are one in the same as the country, and so to protect us, the country must be protected as well. We don't need to just be protected from invading armies. We need to be protected from falling behind in the world as well, and that means more than just the military. In order to ensure a future for our nation (which is really why you're protecting it in the first place), you must have a basic framework within which people can live. Our people need to be educated in order to remain competitive in this global economy, therefore the government's job is also to provide basic education to its citizens. We need businesses to make and sell products that let us live our daily lives, and we need to be protected in case they grow too big. Therefore the government's job is also to create an economic infrastructure (the treasury and the mint), transportation (so that people have the freedom to travel and goods can get to where they need to be), telecommunications (or at least regulation thereof, so that people have the freedom to communicate with other people, and businesses can get their jobs done), welfare (because a temporarily unemployed person with no income cannot afford to pay bills, and therefore puts no money back into the economy, which does nothing for our nation. after a certain point, they become a drain on the economy, but welfare can be good when done properly), and taxation (because providing all of these services costs money).

  28. Re: Role of Federal Gov't (offtopic but....) by shadow_slicer · · Score: 2, Insightful
    As far as I'm concerned, the government's 1 and only job is to protect us so that we can live our lives however we choose.
    Just ask yourself when was the last time that the US was actually threatened.
    I'm not talking small incidents (like 9/11), I'm talking threats to the nation's existence; the last time I can think of is WWII.

    If you can be bothered to read the constitution then you would realize that America was never designed to have a standing military. The only purpose of the military was to combat a real threat to the nation (ie war). If you think about it this way, the US has been in a state of "war" for over 60 years...which seems kind of ridiculous...

    Having a standing military gives the Executive branch too much power--it can declare war without bothering to worry about what Congress or the other branches think (not to mention the people of the nation).

    Also, the federal government's role is not limited to the defense of the nation. If you read the preamble, it's purpose might be more clear.

    Constitutional quibling aside, wouldn't you want your federal government to be able to protect you when the aliens come?
  29. So what? Jupiter has spots by Chocolate+Teapot · · Score: 2, Funny

    If people keep pointing it out, it is only a matter of time befor Jupiter starts developing a negative self-image. It is then only a matter of time before Jupiter stomps off sulking and slamming doors, taking it's vast gravitational field with it and leaving us to collect our own space junk.

    --
    Modest doubt is called the beacon of the wise. - William Shakespeare
  30. Goatse??? by Christopher_G_Lewis · · Score: 2, Funny

    Am I the only one who was afraid to click on the link?