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  • Here's this planet with all these incredible storms going on. It's that awe when you're

  • confronted with something that's completely natural, no human had any hand in it. I think

  • it gives you a sense of the power of nature. One of the most resourceful digital cameras

  • to ever travel beyond Earth is capturing hidden regions on Jupiter for the first timeTo

  • get these photosengineers had to build a nearly indestructible camera that could

  • survive in one of the harshest environments in our solar system.

  • You're looking at the closest image of the Great Red Spot ever takenSnapped by JunoCam, a deceptively

  • small camera aboard this NASA probeIt was launched in 2011 and has been orbiting Jupiter

  • since 2016 with a special purpose: to share previously unseen regions of Jupiter and connect

  • humanity with its celestial neighborThe person who is now the principal investigator

  • on Juno, Scott Bolton was convinced that we should not fly a spacecraft to Juno without

  • a camera. He enlisted me then to help him get a camera on this spacecraft. But because

  • there was no need for a science investigation JunoCam turned into an outreach camera.

  • It would become the eyes for NASA and the world, as we ventured closer to Jupiter than all

  • previous missions. But because of its role as an outreach tool, resources were limited.

  • The more challenging side was that the camera was really kind of left with what was a rather

  • constrained set of resources. Because the science instruments needed mass, power, volume.

  • And as a result, we were not able to put a big telescope on the front. If you look at

  • other missions that have flown by or orbited Jupiter, one of the things they all have in

  • common is they have substantial telescopes. And we just knew that was out of question.

  • So the team went to the drawing board with a few specific requirements for the camera.

  • We want to take a picture over the poles. We are not going to be able to build up a mosaic

  • of imageswe have to capture the entire pole in one image and we want it to be colored.

  • Red, green, blue. And we don't want it to be too murky, there's not a lot of sunlight

  • at the poles. I also knew at that time that Juno was going to be a spinning spacecraft.

  • Juno's constant rotation ensures stability during the journey and guarantees that the scientific

  • instruments aboard are in the best position to observe JupiterPlus, they had to plan

  • for the unforgiving environment. Jupiter has a very powerful magnetic field. There's a

  • lot of charged particles, electrons, protons, heavier ionsAnd those can damage electronic

  • detectors, and they can turn lenses brown, and there's a lot of consequences. So we had

  • to protect the camera from all of that. At the end of the design and construction stage,

  • the team built a camera called a push frame imagerWhat that means is only a little

  • bit of the planet is imaged at any given instant in time. The field of view is quite wide.

  • It's 58 degrees, which is very unusual for the typical kinds of cameras that you put

  • on spacecraft. The camera, however, isn't snapping pictures at every momentThe spacecraft

  • is in a 53 day orbit, so it's very elliptical and the spacecraft spends most of its time

  • very distant from JupiterBut every 53 days it comes in close and we first fly over the

  • North pole, two hours later the spacecraft is passing the South pole and as we go by

  • our closest approach we're just really just skimming the cloud tops. We're so close Jupiter's

  • in our face where not only do you see the storm, you see the context of the storm, and

  • you see the winds around the storms. Only when JunoCam is traveling through this small

  • window of time does it finally get to workAs the spacecraft is rotating the reflected sunlight

  • off of Jupiter comes down the optics, goes through one of those color filters, and then

  • it gets turned into these levels of gray. That all gets stored onboard the spacecraft

  • as a series of ones and zeros and then it gets transmitted from the spacecraft memory

  • to Earth using radio waves. And then the bytes are turned into lines of an image. So it's

  • like you've got Jupiter, you turn it into a jigsaw puzzle, and then you put the puzzle

  • back together again on Earth. We do not have a classic imaging science team

  • and we count on the public to be our virtual imaging team.

  • This is where citizens from all over the world step in to process the images that

  • JunoCam takesWe have the super expert folks that want to start with the raw data and then

  • we have people who want to pull an image into Photoshop and they might change the color

  • balance or they might exaggerate the color. I mean it's as limitless as people's imaginations.

  • And while the camera was originally intended to increase public engagementit turns out

  • that you could do really very interesting science with our little outreach camera.

  • No spacecraft had ever imaged the polar regions, because most spacecraft stay in the equatorial

  • zone and the first thing we discovered are that there are cyclones around the polesWe're

  • studying the atmospheric circulation and it turns out these structures are very stableSo

  • that's teaching us about the circulation patterns around the pole, how deep they go

  • and how the polar regions link dynamically speaking to the lower latitudes

  • that we're much more familiar with.

  • So little by little, the data's being analyzed scientifically and the papers are being written.

  • If you look at Jupiter through a telescope it's kind of pastel. It's kind of a yellowish,

  • but very subtle colors. With the public's help, JunoCam images have shaken up conventional

  • wisdom around what Jupiter looks likeYou put that in the hands of an artist, and suddenly

  • it's deep blues, and dark browns and everything that you see in those images is there.

  • But when the color is exaggerated, it's like you're getting punched in the nose with it.

  • Right now our mission is scheduled to come to an end somewhere in 2021, but because all of

  • the instruments are doing well and the spacecraft is doing well in Jupiter's radiation environment,

  • we're starting to look at how to extend the mission. We'll see how long it goes, but right

  • now, there's no end in sight.

Here's this planet with all these incredible storms going on. It's that awe when you're

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美國宇航局這臺堅不可摧的相機揭示了木星上隱藏的圖案 (This Indestructible NASA Camera Revealed Hidden Patterns on Jupiter)

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    林宜悉 發佈於 2021 年 01 月 14 日
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