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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 eno

by neals 10y ago

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?

jessriedel 10y ago
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't know the resolution. But this photo was taken from 2.7M miles, so you can expect the resolution to get roughly 9 thousand times better. EDIT: > Jupiter itself will only appear to be 75 pixels across from JunoCam when Juno reaches the furthest point of its orbit around the planet. At its closest approaches JunoCam could achieve 15 km/pixel resolution from 4300 km, while Hubble has taken images of up to 119 km/pixel from 600 million km....The camera uses a Kodak image sensor, the KODAK KAI-2020, capable of color imaging at 1600 x 1200 pixels. It has a field of view of 18 x 3.4 degrees with three filters to provide color imaging. https://en.wikipedia.org/wiki/JunoCam https://en.wikipedia.org/wiki/JunoCam
- chaitanya 10y ago
  > At its closest approaches JunoCam could achieve 15 km/pixel resolution from 4300 km In comparison, the highest resolution photos of Pluto from New Horizons achieved 80 meters per pixel from a closest approach of 12500 km. Its amazing how good the camera was on New Horizons. https://www.nasa.gov/feature/new-horizons-best-close-up-of-plutos-surface https://www.nasa.gov/feature/new-horizons-best-close-up-of-p...
  - jessriedel 10y ago
    No doubt New Horizon's camera was phenomenal for the mission, but I'm actually not sure how good it was compared to something you could do with a terrestrial lens. (There are lots of compromises when you go to space.) Juno's camera is very modest by design: It's a wide-field of view and only a few megapixels, so basically a cell-phone camera.
    - jonknee 10y ago
      > 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).
      - valarauca1 10y ago
        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.
        jonknee 10y ago
        Yup, that's what those big pixels are good for.
      - jessriedel 10y ago
        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".
        pwthornton 10y ago
        It's the opposite of cellphone camera. It has low megapixels and a large sensor size. This will allow a lot of light onto the sensor and it won't suffer from the noisiness that high megapixels on a smaller sensor suffer from.
        jessriedel 10y ago
        The point is that, on the spectrum of all imaging devices you might put on a satellite, both Juno and a cell phone camera are in the same rough neighborhood. They are dwarfed by telephoto lens, or 200 megapixel sensors. Remember especially that the topic we are discussing is the resolution (km/pixel) at a particular distance (see above), and for this the lens are much more important than the particular CCD chosen.
- deleted 10y ago
  [deleted]
- dougmany 10y ago
  >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.
- JoeAltmaier 10y ago
  In fact I believe Juno has ice-penetrating radar, intended to probe for the mythical surface. We may be seeing images of its real surface for the first time soon
  - mturmon 10y ago
    I do not believe radar is part of the instrument set. There is a "gravity sensor" which is really, I think, an extremely careful Doppler measurement which will allow us to infer the mass distribution within Jupiter.
    - JoeAltmaier 10y ago
      Yeah you're right. I was remembering the Europa probe I think. They did parts of both at the local University some years back.
valarauca1 10y ago
>Are we going to get amazing Pluto-like images, like that chilling closeup? No. The camera on Juno was literally an after thought. Originally it wasn't even going to have one. It's main job is studying magnetic fields and radiation belts.
- mturmon 10y ago
  Yes, the optical-wavelength camera was not a science driver for Juno. It's just making images of cloud tops. The cloud tops aren't that interesting, it's what's going on underneath or beyond. In addition to fields and radiation instruments you mention, there are two other imaging spectrographs, one an IR instrument and one in UV. The IR camera can look ~70 km down below the cloud tops. Importantly, there is a microwave radiometer, which can peer ~500km beneath the clouds to determine atmospheric composition as a function of time and space. They have put Juno in a polar orbit, so it will scan the atmosphere through dozens of orbits before the radiation kills the instruments.
ridgeguy 10y ago
We should get some extraordinary views of Jupiter's polar aurora activity. Also much higher resolution of gas dynamics phenomena because of Juno's perijove altitude of ~3,000 miles. Doubt we'll see depth, unless it's through fortuitous breaks in high clouds. Other (non-imaging) instruments (microwave sounders, etc.) will tell us what's going on in Jupiter's interior. Metallic hydrogen? Rocky core? Juno may tell us.

by neals 10y ago

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?

jessriedel 10y ago

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't know the resolution. But this photo was taken from 2.7M miles, so you can expect the resolution to get roughly 9 thousand times better. EDIT: > Jupiter itself will only appear to be 75 pixels across from JunoCam when Juno reaches the furthest point of its orbit around the planet. At its closest approaches JunoCam could achieve 15 km/pixel resolution from 4300 km, while Hubble has taken images of up to 119 km/pixel from 600 million km....The camera uses a Kodak image sensor, the KODAK KAI-2020, capable of color imaging at 1600 x 1200 pixels. It has a field of view of 18 x 3.4 degrees with three filters to provide color imaging. https://en.wikipedia.org/wiki/JunoCam https://en.wikipedia.org/wiki/JunoCam

chaitanya 10y ago
> At its closest approaches JunoCam could achieve 15 km/pixel resolution from 4300 km In comparison, the highest resolution photos of Pluto from New Horizons achieved 80 meters per pixel from a closest approach of 12500 km. Its amazing how good the camera was on New Horizons. https://www.nasa.gov/feature/new-horizons-best-close-up-of-plutos-surface https://www.nasa.gov/feature/new-horizons-best-close-up-of-p...
- jessriedel 10y ago
  No doubt New Horizon's camera was phenomenal for the mission, but I'm actually not sure how good it was compared to something you could do with a terrestrial lens. (There are lots of compromises when you go to space.) Juno's camera is very modest by design: It's a wide-field of view and only a few megapixels, so basically a cell-phone camera.
  - jonknee 10y ago
    > 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).
    - valarauca1 10y ago
      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.
      - jonknee 10y ago
        Yup, that's what those big pixels are good for.
    - jessriedel 10y ago
      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".
      - pwthornton 10y ago
        It's the opposite of cellphone camera. It has low megapixels and a large sensor size. This will allow a lot of light onto the sensor and it won't suffer from the noisiness that high megapixels on a smaller sensor suffer from.
        jessriedel 10y ago
        The point is that, on the spectrum of all imaging devices you might put on a satellite, both Juno and a cell phone camera are in the same rough neighborhood. They are dwarfed by telephoto lens, or 200 megapixel sensors. Remember especially that the topic we are discussing is the resolution (km/pixel) at a particular distance (see above), and for this the lens are much more important than the particular CCD chosen.
deleted 10y ago
[deleted]
dougmany 10y ago
>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.
JoeAltmaier 10y ago
In fact I believe Juno has ice-penetrating radar, intended to probe for the mythical surface. We may be seeing images of its real surface for the first time soon
- mturmon 10y ago
  I do not believe radar is part of the instrument set. There is a "gravity sensor" which is really, I think, an extremely careful Doppler measurement which will allow us to infer the mass distribution within Jupiter.
  - JoeAltmaier 10y ago
    Yeah you're right. I was remembering the Europa probe I think. They did parts of both at the local University some years back.

valarauca1 10y ago

>Are we going to get amazing Pluto-like images, like that chilling closeup? No. The camera on Juno was literally an after thought. Originally it wasn't even going to have one. It's main job is studying magnetic fields and radiation belts.

mturmon 10y ago
Yes, the optical-wavelength camera was not a science driver for Juno. It's just making images of cloud tops. The cloud tops aren't that interesting, it's what's going on underneath or beyond. In addition to fields and radiation instruments you mention, there are two other imaging spectrographs, one an IR instrument and one in UV. The IR camera can look ~70 km down below the cloud tops. Importantly, there is a microwave radiometer, which can peer ~500km beneath the clouds to determine atmospheric composition as a function of time and space. They have put Juno in a polar orbit, so it will scan the atmosphere through dozens of orbits before the radiation kills the instruments.

ridgeguy 10y ago

We should get some extraordinary views of Jupiter's polar aurora activity. Also much higher resolution of gas dynamics phenomena because of Juno's perijove altitude of ~3,000 miles. Doubt we'll see depth, unless it's through fortuitous breaks in high clouds. Other (non-imaging) instruments (microwave sounders, etc.) will tell us what's going on in Jupiter's interior. Metallic hydrogen? Rocky core? Juno may tell us.