First Science Results from NASA’s Juno Mission | Hacker News Reader

First Science Results from NASA’s Juno Mission

nasa.gov

109 pointsrgbrenner27 comments

The lifetime cost of this mission is $1.1B.

For the price of a space shuttle program, we could get 200 of these. ISS is worth 100 of these.

If we're really serious about space exploration, robot probes and telescopes give by far the biggest bang for the buck, and they go where no human being can ever go. That Jupiter flyby would cook you like an egg.

Robotic missions won't make us a multiplanetary society though (neither does the space shuttle...). I think that's important too.

I am 100% certain it will be robots that construct the first habitats for any future Mars or Moon inhabitants. As much as I want an interplanetary future for humanity, the case for concentrating on robotic exploration is just too strong to not have them be the primary focus of development for now.

Not to the exclusion of humanity, mind you. But to do the work to get to the point where we can confidently send people on a mission that isn't either temporary or suicide.

Sure, robots are important, but it's not robots circling around Jupiter that we need to build. We're already pretty good at that. There doesn't seem to be any serious money for developing robots that help with the construction of habitats for humans.

Not directly for those purposes, sure.

But it isn't much of a skip to see future derivatives of mil-sponsored research like Boston Dynamic's Atlas and Big Dog being put to use as workers in hostile environments, both here on Earth and in space. The civilian space program would never have gotten as far as it has without massive transfer from the military spending on boosters, after all, so the direction of transfer has precedent.

A lot of us think that's a specious goal. Earth has oxygen, the food is good, there's decent nightlife. And all my stuff is here.

Luckily humanity has enough resources to pursue multiple goals simultaneously

Not this one. To create an outpost off-planet capable of sustaining human civilization at its current level in the event something happened to Earth would consume our entire economic output for many years, if it were even achievable.

Or it would consume a tiny fraction of our economic output for several generations while maybe also throwing off some sweet tech that is useful back here on Earth.

Do we have that long?

Who knows? Better get started sooner than later.

All your stuff is here, sure. What about your great-grandchildren?

I admire your optimism.

Could just as well be pessimism.

The congressional politics of the districts where the development of human space flight systems are a major employer are, unfortunately, a huge factor in NASA's budget earmarks.

Also known as the "Alabama Space Mafia".

Yanis Varoufakis, Greek Minister of Finance during the Greek debt crises, has suggested that the (somewhat hidden) redistribution of money from the wealthy parts of USA to the poorer part via federal government spending is part of what allows the poorer parts of the USA not have the same level of problems that Greece (and Spain?) has with respect to Germany in the EU. The EU budget is about 1% of European GDP while US federal budget is abut 20% of USA GDP.

The failure of its main engine is going to turn out to be a blessing as fabulous new Jupiter photography every 53 days could be a nice regular treat for us space boffins.

I hadn't heard about this failure, this explains a bit about it https://spaceflightnow.com/2017/02/02/juno-dives-over-jupite...

Beautiful.

I find images of Jupiter absolutely stunning, and that the dynamics behind the auroras is sophisticated (ie, something complex happening above the core) is even more interesting.

I can't wait for Juno to bring us even more results!

Do you know what kind of gas produces the blue we see on the South Pole?

Maybe methane and ammonia, like neptune...

Do you know if these images have been colour-enhanced, like those photos of glowing nebulae? http://www.imagingdeepsky.com/Nebulae/Horsehead/FullSizeJpg/...

Enhanced color isn't exactly right. Most nebula images are done with Narrow Band filters that only let a specific wavelength through. Typically those of Hydrogen alpha, sulfur II and oxygen III emissions. This gives three monochrome channels of data that you can combine however you please to RGB. Or supplement with even more data from broadband R, G, B or luminance filters. Not sure about the Horsehead image, could be a HaRGB or even Near infrared composite. In the case of Juno there are 4 filters: R, G, B and a methane filter (~840nm narrow band). The data you can map to RGB arbitrairly, usually with a linear combination. It's just as much art as science

Thanks. But excuse my dumminess, just need to get this right: so the three channels of data can be converted into RGB to give the "shades" to make a photo ... but you can pick a dominant colour filter, like blue, green or in the Horsehead's case, pink?

I am mesmerised by Juno's photos but wondering if it's true to the human eye (like as if we are there.) The photo caption hints otherwise [1] but I'm not sure if my understanding is correct!

[1] Multiple images taken with the JunoCam instrument on three separate orbits were combined to show all areas in daylight, enhanced color, and stereographic projection.

Basically, each narrow-band filter gives you a grey-scale image. You can assign whatever color you like to each of them, and then mix them to get a color image. If you have filters for the Red, Green, and Blue wavelengths, and then apply Red, Green, and Blue colors of the same wavelength to the images before mixing them, that'll get you as close to a true-color image as possible. (That's essentially what's going on in your camera, for capturing an image and then displaying it to you.)

Red, Green, and Blue are used because their wavelengths match the wavelengths that the cells in our retinas are sensitive to. That allows cameras to approximate human vision. But scientists use lots of other wavelengths too in order to see specific things more clearly, like Juno's methane filter. Every chemical gives off specific wavelengths of light when it releases energy, so filters that are tuned to those wavelengths make it easier to detect those chemicals. (I'm simplifying a bit here.) The false-color images you see from these missions are designed to combine multiple filters (that aren't RGB) and mix them using contrasting colors so that you can still see highlights from each of the filters.

A simple explanation: converting IR-images to "human-color" images. [1]

Your eyes don't see the Infrared, so you apply some conversion where the infrared scale is converted to some color scale, and you know that where you see more red (for example) means that you're seeing where the infrared was stronger.

[1] https://en.wikipedia.org/wiki/Infrared_photography

> wondering if it's true to the human eye

Not really connected to your main question, but here goes -

The point is moot in the case of the Horsehead Nebula. The image is so dim (in the eyepiece of a telescope) that the human eye cannot perceive colour.

Also, it's a lot smaller in the eyepiece than most people expect - so it's pretty easy to miss.

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