Huge Storms Converge on Jupiter 205
tpoker writes to tell us NASA is reporting that the two biggest storms in the solar system are about to collide on Jupiter. From the article: "Storm #1 is the Great Red Spot, twice as wide as Earth itself, with winds blowing 350 mph. The behemoth has been spinning around Jupiter for hundreds of years. Storm #2 is Oval BA, also known as 'Red Jr.,' a youngster of a storm only six years old. Compared to the Great Red Spot, Red Jr. is half-sized, able to swallow Earth merely once, but it blows just as hard as its older cousin."
Re:Nice job, editors! (Score:3, Informative)
Except for the whole basic math thing.
If one object is two earths wide, and another object is one earth wide, the 2nd object is one FOURTH the size of the first, not one half.*
* Assumes objects are of the same shape and the shape is uniform in one dimension. Which should be pretty good assumptions in this case.
Collide? (Score:5, Informative)
I guess the summary was a little bit of a hyperbole. Esp. for an event that happens every two years.
Re:Collide? (Score:4, Informative)
Re:Collide? (Score:5, Informative)
What signifies about this particular encounter is that the small oval is thought to be intensified its strength recently (when its color changed from grey to red) and that just *might* cause a bit more interesting interaction between these two storms (when they pass by closely). It's a pure speculation based none other than intuition of scientists. Not based on a hydrodynamic simulation; just a wild ass guess on their part.
Of course, they wouldn't say that. That'd make this whole thing, well, boring.
Re:Pretty Sweet "Amateur" Telescope ..? (Score:5, Informative)
You are not going to get Hubble or Voyager level views. Many amatures now digitally enhence their images such that you see more in the photo than what the eye would see in the scope. One fairly recent technique is to take hundreds of digital images and then digitally average and realign the detail. The Earth's atmosphere wiggles and sometimes acts kind of like a magnifying lens. If you can capture these magnification spots when they occure and add them up, you get a nice photo.
Anyhow, I would guess that you need at least an 8-inch reflector or 5-inch refractor to see the two spots with recognizable detail. It also depends on sky conditions and viewer training. It takes a while to train the eye to see detail on planets thru a scope.
Re:Pretty Sweet "Amateur" Telescope ..? (Score:2, Informative)
Re:Pretty Sweet "Amateur" Telescope ..? (Score:3, Informative)
If your telescope is 10inch (~ 250mm), then your maximum magnification achievable with your telescope is up to 250 times. You can increase the magnification as much as you like (by the choice of an eyepiece), but it doesn't mean a damned thing when you go beyond 250x for the 10in telescope (it's like examining a photo on a magazine with 10000x magnifying glass; i.e., it's meaningless). For a 6inch telescope (~ 150mm), the max is 150x or so.
A 3in telescope is enough to see the Great Red Spot. For the small oval, it'd take a bigger telescope, I'd guess.
Re:Collide? (Score:5, Informative)
Fluid dynamics, particularly on such a massive scale as storms on a planet like Jupiter, is still largely a matter of wild ass "guess"timates. With good reason.
The basic equations of fluid mechanics, the Navier-Stokes equations, are a second order, non-linear system of partial differential equations. Atmospheric gases are also compressible flows. Couple this with aerosols, rotation of the planet, and mondo awkward boundary conditions due to the surface curvature; it's lack of a crust; and the lack of a defined "end" of the atmosphere, finally sprinkling a generous dose of chaos theory in to account for sensitivity to initial conditions.... and you've got a problem that is to all intents and purposes, completely unsolvable.
And that's "just" the fluid dynamics problem. And the continuum hypothesis isn't the only way to solve it. You could use Lagrangian mechanics if one were so inclined.
And these are just theoretical issues. We haven't even spoken about the practical difficulties. First and foremost, throw hope for an analytic solution out the window, because it's not going to happen. You've got to go with a numerical solution. Which brings up the next question of which numerical techniques to you use, and how accurately do you use them. You've got to factor in time, cost and cpu ability. You'll have to parrallelise the whole deal, and make sure it's accurate enough to remain stable for long enough to predict but you want but quick enough so that you'll get your answer before the actual event happens.
And last, but by no means least, once you've got that data, how do you analyse it? How do you even present it? Remember, we're talking about 3d vortices here, embedded in a globe. How do you make sense of it all. What points are of interest? What events are key? What can you learn from all this? What size font should the image titles have? How will you make a paper out of all this!?
Faced with such an operation, you're often better off performing a simulation when faced with a fluid mechanics problem, or in the case where simulation is impossible such as with Jupiter, just make a wild assed guess, sit back and enjoy the show.
Re:Collide? (Score:3, Informative)
Codswallop.
Hurricane forecasts on earth diverge the further out you get. None of them called the right turn Katrina pulled in the Gulf of Mexico before she first hit Florida. On 8/25/05, this was the forecast:
Notice New Orleans isn't even mentioned?
Those models had thousands of data point samples to work with including multiple flights into the heart of the hurricane and they still couldn't agree, let alone accurately forecast what happened to New Orleans. Those 'initial parameters' you so blithely dismiss have to be very accurate to make 24 hour forecasts, let alone forecast what's going to happen a month from now on a planet for which we have exactly zero weather buoys.
Mod parent up... (Score:3, Informative)
Sean