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NASA’s Juno Spacecraft Sends First In-orbit View

nasa.gov

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Re: NASA’s Juno Spacecraft Sends First In-orbit View

#71

Post by jonknee »

valarauca1 wrote: post #37
jonknee wrote: post #32

Earlier quoted context omitted.

> It's a wide-field of view and only a few megapixels, so basically a cell-phone camera. It's not similar to a cell phone camera at all. Cell phone cameras are usually much higher resolution (current iPhone is 8 megapixels vs the 2 for Juno), but with a much smaller sensor (iPhone cam has a 1.5µm pixel size vs 7.4µm for Juno).

Also light thresholds need to be taken into consideration. Jupiter is 5x[1] further from the Sun then Earth, so there is much less light to capture in an image. [1] On average.

Yup, that's what those big pixels are good for.

Re: NASA’s Juno Spacecraft Sends First In-orbit View

#72

Post by InclinedPlane »

drzaiusapelord wrote: post #35
KnightOfWords wrote: post #10

Glad Juno has made it and appears to be working OK. Not the most amazing image, better ones are routinely taken by amateurs from earth, but the crescent can only be seen by going there as Jupiter lies outside our orbit. We'll see much closer views from Juno when it's moved to a closer orbit in October. I came across this on Reddit the other day, taken with a smartphone and 8" telescope: https://www.reddit.com/r/astro…

>Stacked 400 best in Autostackert This isn't a photo. It a photoshop fiction of 400 different photos blended together. There's a big difference between that and a single frame from a spacecraft. Comparing the two seems silly.

It's not a fiction, nor is it "photoshop", it's actual data.

The basic problem of all astronomy from Earth's surfaces is that the atmosphere impedes seeing. So much so that even small backyard telescopes rapidly reach the limit of atmospheric seeing before hitting the limits of diffraction. There are several ways around this. One is to leave the atmosphere entirely, resulting in the stunning capabilities of space based observatories like Hubble. Another is adaptive optics, which relies on various techniques to read the atmospheric disturbance causing degraded seeing and precisely counteracting it by interposing a reactive optical element.

The technique in question is basically a sort of poor man's adaptive optics related to speckle imaging (another technique employed for the same purpose). For bright objects (like planets) an image exposure using modern CCDs need only be a fraction of a second. Which provides the opportunity to collect many of them over a period of time, which is something that many cameras already do quite well by recording video. The alternative of counteracting poor atmospheric seeing is to hope you get lucky and capture a moment where atmospheric distortion is at a minimum. Such moments are rare and fleeting, but over the course of hundreds or thousands of images from a video stream, there will be a few. The trick is to find the best moments of seeing for a given portion of the image from within the frames and combine all of them together into a single image. You then have essentially a "dream team" of atmospheric seeing conditions for every part of the image. Every part is real, and the overall image is a true representation, not a fantasy.

However, your point about the futility of comparing the two is accurate. Comparing a single image from Juno to the best thing produced from a backyard astronomer ever is not a good comparison. Especially since Juno will collect a great many more pictures and is not at all optimized for taking pictures at its current distance from Jupiter. The best pictures of Jupiter from Juno will outclass anything we've taken with any instrument from any observatory or spacecraft so far, but it'll be a while yet before we have those.

Re: NASA’s Juno Spacecraft Sends First In-orbit View

#73

Post by cryptoz »

drzaiusapelord wrote: post #33
peter303 wrote: post #28

Earlier quoted context omitted.

SpaceX might launch a Mars lander during the 2018 low energy window. Though I am guessing more likely the 2020 window following that. NASA is fully cooperating with SpaceX by doing things like providing detailed data of previous Mars landings. NASA is SpaceX largest customer and financier. Many ex-NASA people workmat SpaceX. These data are public. But it helps to have good communication channels.

>SpaceX might launch a Mars lander during the 2018 low energy window. Is this budgeted? Is it on a launch docket? Is there a rocket ready for it? Is the lander completed? 2018 is right around the corner and frankly I'm getting sick of "Spacex might" comments. There's a big difference between "might" and "do." When you see a mission on the NASA roster, its ready to go and unless there's some serious technical issue, i…

> Is this budgeted?

Yes.

> Is it on a launch docket?

Yes.

> Is there a rocket ready for it?

It's being built right now, the test is in December.

> Is the lander completed?

It's being built right now, the test is soon.

> 2018 is right around the corner and frankly I'm getting sick of "Spacex might" comments.

SpaceX has completed every single thing they have ever said they would do, except for things that remain in the future. I don't know how you could be sick of "SpaceX might" because it generally means "SpaceX will".

> I'd like to see more "do" from SpaceX that isn't LEO flights and landing on barges.

They're planning on colonizing Mars by sending 80,000 people per year until there are millions living on Mars. They have been working steadily towards that goal for 15 years. They are extremely busy and making the most rapid progress in spaceflight since the beginning of spaceflight itself. Take a step back and realize how much SpaceX is actually doing. If this isn't enough "do" for you, then I think nothing in the world or anywhere in the solar system would satisfy whatever you're looking for.

Re: NASA’s Juno Spacecraft Sends First In-orbit View

#74

Post by jessriedel »

jonknee wrote: post #67
jessriedel wrote: post #38

Earlier quoted context omitted.

Um, so the best cell phone camera on the market is within a factor of 2 in linear resolution? I think that qualifies as "basically".

Resolution has very little to do with it. Many images from NASA are stitched, even the ones from New Horizons. The important part is light sensitivity (in the correct wavelengths!) and making sure that it can work in the radiation of Jupiter. You can go buy a camera with the same sensor if you'd like, but they're expensive: http://www.qsimaging.com/620-overview.html I believe it's the same sensor that flew on the Cur…

As you'll see if you look above, it was you who brought about the size of the sensor when critiquing my comment, which was addressing resolution.

You also seem to feel the need to defend Juno, as if I was attacking it somehow, so I don't think this conversation can be very productive.

Re: NASA’s Juno Spacecraft Sends First In-orbit View

#75

Post by DavidWanjiru »

drzaiusapelord wrote: post #35
KnightOfWords wrote: post #10

Glad Juno has made it and appears to be working OK. Not the most amazing image, better ones are routinely taken by amateurs from earth, but the crescent can only be seen by going there as Jupiter lies outside our orbit. We'll see much closer views from Juno when it's moved to a closer orbit in October. I came across this on Reddit the other day, taken with a smartphone and 8" telescope: https://www.reddit.com/r/astro…

>Stacked 400 best in Autostackert This isn't a photo. It a photoshop fiction of 400 different photos blended together. There's a big difference between that and a single frame from a spacecraft. Comparing the two seems silly.

If I'm not mistaken, they use a similar technique to makes satellite images of earth that don't have cloud cover, or maps without cars and stuff, yet we know it is highly likely these were present when pictures were taken. So it's not fiction.

Re: NASA’s Juno Spacecraft Sends First In-orbit View

#76

Post by mikestew »

drzaiusapelord wrote: post #35
KnightOfWords wrote: post #10

Glad Juno has made it and appears to be working OK. Not the most amazing image, better ones are routinely taken by amateurs from earth, but the crescent can only be seen by going there as Jupiter lies outside our orbit. We'll see much closer views from Juno when it's moved to a closer orbit in October. I came across this on Reddit the other day, taken with a smartphone and 8" telescope: https://www.reddit.com/r/astro…

>Stacked 400 best in Autostackert This isn't a photo. It a photoshop fiction of 400 different photos blended together. There's a big difference between that and a single frame from a spacecraft. Comparing the two seems silly.

Don't ever use the HDR function on your camera, then. For that matter, you'd probably want to avoid digital cameras in general unless you're RAW-only.

Re: NASA’s Juno Spacecraft Sends First In-orbit View

#77

Post by gherkin0 »

jonknee wrote: post #67
jessriedel wrote: post #38

Earlier quoted context omitted.

Um, so the best cell phone camera on the market is within a factor of 2 in linear resolution? I think that qualifies as "basically".

Resolution has very little to do with it. Many images from NASA are stitched, even the ones from New Horizons. The important part is light sensitivity (in the correct wavelengths!) and making sure that it can work in the radiation of Jupiter. You can go buy a camera with the same sensor if you'd like, but they're expensive: http://www.qsimaging.com/620-overview.html I believe it's the same sensor that flew on the Cur…

That's actually way cheaper than I expected it to be. Though I supposed an actual spaceflight-worthy camera with that sensor would cost far more than the one you linked.

Re: NASA’s Juno Spacecraft Sends First In-orbit View

#78

Post by dougmany »

jessriedel wrote: post #18
neals wrote: post #17

Are we going to get amazing Pluto-like images, like that chilling closeup? They really impressed me A LOT. Or is Jupiter close enough for us to already know enough about its surface?

Jupiter either doesn't have a solid surface, or it lies very deep inside (like 4/5ths of the way to the center). So there isn't any surface to see, just clouds. Juno will be passing within 3,000 miles of the tops of Jupiter's clouds. Since Jupiter's radius is 43,000 miles, it will fill the entire frame. The only question is how high-quality the camera is. The camera is for public relations only (no science) and I don…

>The camera is for public relations only

This statement made my day. I guess if a phone must have a camera on it then a spacecraft has to have one too.

Re: NASA’s Juno Spacecraft Sends First In-orbit View

#79

Post by jonknee »

jessriedel wrote: post #74
jonknee wrote: post #67

Earlier quoted context omitted.

Resolution has very little to do with it. Many images from NASA are stitched, even the ones from New Horizons. The important part is light sensitivity (in the correct wavelengths!) and making sure that it can work in the radiation of Jupiter. You can go buy a camera with the same sensor if you'd like, but they're expensive: http://www.qsimaging.com/620-overview.html I believe it's the same sensor that flew on the Cur…

As you'll see if you look above, it was you who brought about the size of the sensor when critiquing my comment, which was addressing resolution. You also seem to feel the need to defend Juno, as if I was attacking it somehow, so I don't think this conversation can be very productive.

> As you'll see if you look above, it was you who brought about the size of the sensor when critiquing my comment, which was addressing resolution.

Because sensor size is what's important in digital photography, you can always stitch together multiple images to get more resolution. A large sensor like what's flying on Juno is orders of magnitude better than a camera phone sensor regardless of the resolution. In general cell phone cameras (which you decided to compare Juno's to) are high resolution, but with small a sensor (everything in a phone is small!). Juno is the opposite, low resolution and a large sensor. If you want to take pictures of stuff in space you most certainly want a large sensor.

> You also seem to feel the need to defend Juno, as if I was attacking it somehow, so I don't think this conversation can be very productive.

Well you did attack it by saying its camera was the same quality as a camera phone (aka cheap and shitty). It's not similar to a camera phone whatsoever, you were just plain wrong.

Re: NASA’s Juno Spacecraft Sends First In-orbit View

#80

Post by jonknee »

gherkin0 wrote: post #77
jonknee wrote: post #67

Earlier quoted context omitted.

Resolution has very little to do with it. Many images from NASA are stitched, even the ones from New Horizons. The important part is light sensitivity (in the correct wavelengths!) and making sure that it can work in the radiation of Jupiter. You can go buy a camera with the same sensor if you'd like, but they're expensive: http://www.qsimaging.com/620-overview.html I believe it's the same sensor that flew on the Cur…

That's actually way cheaper than I expected it to be. Though I supposed an actual spaceflight-worthy camera with that sensor would cost far more than the one you linked.

Yup, they made a custom camera (which makes sense!). All the way at the bottom of this page there are photos of it along with a lot of details:

http://spaceflight101.com/juno/instrument-overview/

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