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New Horizons Probe's Images of Jupiter

Posted by kdawson on from the by-Jupiter dept.

SeaDour writes "The Pluto-bound New Horizons space probe, launched a little over a year ago, recently succeeded in passing through a narrow navigational keyhole by Jupiter. Using the gas giant's tremendous gravity, the craft now has a significant boost toward its final destination, shaving three years off the time it would otherwise spend en-route. As it passed through the Jovian system, the probe took some fantastic images of the neighborhood, including detailed observations of erupting volcanoes on Io, time-lapse photography of Jupiter's tumultuous atmosphere, and the faint ring system that was first discovered in Voyager photography. These new images prove the capabilities of the small probe, which is set to reach Pluto in 2015."

12 of 86 comments (clear)

  1. Gravitational slingshot by absolutely · · Score: 5, Informative

    And as we all know, it is Jupiters orbital velocity that gives the spacecraft its speed boost, not Jupiter's gravitational field. See: here.

    1. Re:Gravitational slingshot by Anonymous Coward · · Score: 4, Interesting

      You don't know what you are talking about, and the Wikipedia article is screwed up as well. The Wikipedia article claims that no momentum can be gained passing by a stationary massive object. I'll give a simple counterexample. Drill a bore straight through the diameter of the Earth. If you pull a vacuum in this theoretical bore and drop a spacecraft into it, it will exhibit simple harmonic motion. What is interesting is that the object will have the greatest absolute momentum at the center of the Earth. Now take a rocket and fire only towards the center of the planet when you pass outwards from the center--not inwards. If you do this long enough you will reach escape velocity and say bye bye to the planet. Do your math calculating the momentum and you will find that you have got more absolute momentum that just from the rocket alone.

      Why is this so? First, momentum is conserved, the extra momentum is in the Earth in the opposite direction. Second, you were able to amplify your momentum because you minimized the time that your spacecraft felt the strongest gravitational fields pulling it back towards the planet when you were heading outwards (by using your rocket). But you maximized the time that your spacecraft felt the strongest gravitational fields pulling you into the planet when you were heading inwards coasting (because your rockets only fire when you are heading outwards). Strictly speaking the Earth does not give a great example of how this would work since the highest gravity of the non-uniform density Earth is about 1000 miles under the surface (and is 0 at the core due to Gauss' Law). But it may be more obvious if you arbitrarily move the 'bore' or path of the spacecraft so that its closest approach to the Earth is 2000 km above the surface. In this case it is obvious that you would coast until you got to the closest approach to the Earth and then fire your rockets for a few minutes to minimize your time in the highest gravitational field.

      This is sort of what a flyby could do if it didn't use its rockets and the planet had a high orbital velocity. Due to the orbital velocity alone you could target your spacecraft so that the planet recedes minimizing your gravitational interaction on the flip side (which requires you to fly by close enough to change paths a little bit since no path change would not do anything even with a high speed massive object). Of course using rockets and this method together are better.

    2. Re:Gravitational slingshot by radtea · · Score: 4, Interesting

      This is for the same reason as you give: it spends less time being slowed on the way out because its speed was higher than when it was falling inward.

      Nope. Think about it in terms of potentials and you'll see why this is not correct. The rocket's loss in gravitational potential energy coming out of the hole is exactly equal to the gain it got going in. It doesn't matter how fast it was moving at the start: the potential changes are determined solely by the source configuration because gravity is a velocity-independent force.

      Remember: Newtonian energy change is equal to the integral of force over distance, not time.

      The GP is correct in that mass discharged by a rocket deep in a gravity well has an added benefit. In terms of energetics you can think of this as being due to the gain in energy you get as the expended fuel falls into the well that you don't have to pay back when the spacecraft comes out of it.

      But there it is also the case that the orbital velocity of the planet generally gives a larger effect, although of course it would be misleading and silly to claim that this is not due to the planet's gravity, because what else would be causing the interaction between the planet and the spacecraft? It is true that if the planet had no orbital velocity nothing very interesting would happen, but the same would be true if it had no gravity. Not that either condition is likely to pertain to real planets.

      --
      Blasphemy is a human right. Blasphemophobia kills.
  2. Re:Great! by suv4x4 · · Score: 5, Insightful

    Seriously? We launch a gajillion dollar probe, chance it in a sling around the largest planet in our solar system to only save 3 years, and we get black and white photos that have more noise than my cell-phone's camera!?

    This is how the first computers looked like. And this is how their "hard drives" looked like.

    It was expensive as hell, and the returns were minimal. They dared to do it first, and to improve upon their experience, so today the neighbor kid can whine how he has to wait entire 7 seconds for his physically accurate and photo realistic 3D racing car simulator game to load the entire race track, complete with realistically behaving crowd, plants and atmospheric effects.

    NASA reached Pluto with a remotely controlled probe deep in space. You ranted in Slashdot. Congratulations to both for your great achievements.

  3. Re:Great! by psaunders · · Score: 5, Funny

    I was actually looking forward to seeing what comes back from the probe. But I hear Pluto is a dwarf planet...the pictures probably won't show much, since dwarves live underground.

    --
    Karma police, arrest this man. He talks in math. He buzzes like a fridge. He's like a detuned radio.
  4. Re:Great! (You must be joking) by posterlogo · · Score: 5, Insightful
    You're kidding right? All high-end scientific cameras are monochromatic (cameras for microscopy and astronomy). This is because a "color" CCD is essentially just an approximation of what a RGB image would look like. For scientific purposes, you do NOT want a fixed color imager to be adding or subtracting data. You want imaging at particular visible wavelengths (as directed by specific filters). If you want to make a color image, you can individually take pictures at 3 visible wavelengths (e.g. RGB) and combine them. This is what the Mars rovers do. Color doesn't automatically equate mean better. Sometimes it means you get prettier images, but they're rarely more valuable than imaging with specific filters. For example, infrared and UV can also be used to image. You don't get the pretty pictures except by false coloring, but you sure as heck get a lot of valuable measurements.


    Nice attempt at a rant/trolling, but maybe you don't know what you're talking about.

  5. Re:Great! by Karthikkito · · Score: 5, Informative

    From the JPL website:

    "This is the last of a handful of LORRI images that New Horizons is sending "home" during its busy close encounter with Jupiter - hundreds of images and other data are being taken and stored onboard. The rest of the images will be returned to Earth over the coming weeks and months as the spacecraft speeds along to Pluto."

    Wait some time for the high-res...they're more interested in making sure the thing works above all else.

  6. Another time-saving measure by Kingrames · · Score: 4, Funny

    Whoop-de-do, slingshotting around Jupiter. They could have shaved a lot more time off the trip by slingshotting around the sun. :)

    But that method is usually only reserved for Starfleet emergencies.

    --
    If you can read this, I forgot to post anonymously.
  7. Re:Great! by Fweeky · · Score: 4, Informative

    Ralph: A Visible/Infrared Imager for the New Horizons Pluto/Kuiper Belt Mission

    "MVIC is composed of 7 independent CCD arrays on a single substrate. It uses two of its large format (5024x32 pixel)
    CCD arrays, operated in time delay integration (TDI) mode, to provide panchromatic (400 to 975 nm) images. Four
    additional 5024x32 CCDs, combined with the appropriate filters and also operated in TDI mode, provide the capability
    of mapping in blue (400-550 nm), red (540-700 nm), near IR (780-975 nm) and narrow band methane (860-910 nm)
    channels."

    You did know that cameras like this take colour shots by merging multiple exposures with different filters applied, right? They're probably using their limited bandwidth to retrieve single exposures from each shot to get a quicker overview of what they've got.

  8. Re:asteroid field by regularstranger · · Score: 4, Funny

    The asteroid fields in Star Wars are not representative of any asteroid fields we are familiar with, just like Natalie Portman isn't representative of any woman who has ever talked to me.

  9. Re:It's both, really by Bastian · · Score: 4, Informative

    If Jupiter didn't exhibit a strong gravitational pull on the probe, it wouldn't be able to have a significant impact on the probe's orbital velocity.

    If Jupiter were not moving w/r/t the sun and the probe, the probe's velocity w/r/t the sun would be no greater after the flyby than before.

    The way I see it, both gravity and orbital velocity are necessary components of the gravitational slingshot, so it's fair to say that it's a combination of the two that give the spacecraft its speed boost.

  10. Re:Great! by iamlucky13 · · Score: 4, Insightful

    Ding, ding, ding!

    NASA (tag-teaming with fweeky): 1
    Slashdot armchair cynic: 0

    I don't suppose the GP has ever tried taking a picture of Jupiter with his fancy camera phone, either. He might find it a little blurry, very grainy, and surprisingly dark. Add in a little radiation and interference from moving through Jupiter's magnetic field and then transmit it 150 million miles, and layer on top of it spectrographic and radar data from the other instruments and you realize the OP's $450 (mass-produced price) cell phone with it's 3mm lens doesn't even count as a toy in comparison.

    When you consider that the best images we have of Pluto currently (from the Hubble) are about 0.0005 megapixels of surface data and that New Horizons will pass a fraction of the distance from Pluto that it did from Jupiter, you begin to understand how much bang-for-the-buck this mission has to offer in understanding a body that may be one of the most numerous and least understood type of objects (KBO's) in our solar system.