An un-edited view of Saturn | Hacker News Reader

An un-edited view of Saturn

virtuallyfun.com

101 pointsjoan_kode34 comments

> Instead they are compressed with Kris Becker’s implementation of Huffman encoding. Thankfully the source to the compression, and various manipulation tools are included in both C & Fortran.

As someone who often helps a spouse decode various police car/bodycams and random retail surveillance formats for court work, that always comes on DVDs, this makes me so jealous.

Imagine... having the source code to decode the image or video format right on the CD. In a portable C format.

And not having to install Windows XP to support whatever proprietary DRM'ed software that no longer has a support page on the internet, after 2hrs trying to get it working in a Windows 10 VM? Then leaving the whole OS VM installed on your laptop because you couldn't be bothered to do it twice...

I wish the local police hired NASA people to set up their systems.

Oh VICAR is not so strange. There was this "weird" habit back then that the file formats (IMG astronomical format does this too) would start with an ASCII-based fixed length header (or the header is variable size, but has a line of text at the start that states the size). Always a multiple of 512 or 1024 bytes too. And then in the header you can literally read (with your human eyes) the format used, how many bits per pixel, the lines width and how many lines and so own.

You can literally write a parser from reading a couple of headers. Of course, it's much better to be provided with software that can handle all the nuisances of the format without having to test it when something fails on you.

Sounds a bit like NetPBM.

I would love to see this decoding ability to be added to something like ImageMagick. It'd be just for the lulz, but to be able to say "Of course we can decode Voyager imagery. Can't you?" would be fun. I can't imagine anyone wasting their time on it, or the maintainers to accept it.

I find the idea of "the planets as they would appear if you were really there" very appealing and have thought about it for years. But "un-edited raw imagery" is just the beginning - surely you can't rely on the unadjusted data having the frequency response of the human eye any more than the heavily massaged pictures one usually sees. It seems like a major project that would take significant expertise to try to reproduce what the human eye would see up close.

ah yes, this is exactly the same reason why "#nofilter" has bothered me: there's always a filter between raw pixel intensities and what is actually captured / displayed as a photo. and that's completely ignoring things like white balance and HDR...

agreed on the appeal of seeing celestial bodies "as if we were actually there"

It wouldn't be that major of a project with today's equipment. Just attach any modern camera. However, most of those missions were designed around equipment available decades before they are actually being used, so they are outdated by today's standards but were high end back then. Also, B&W sensors with filters have so much more resolution than dividing by the RGBG pixel arrangement. Maybe Carl Sagan will have had enough of an impact that future mission will include a "regular" camera specifically for the function of making everything more human relatable.

There's also a limit imposed by the ability to return data to earth. I'm thinking of New Horizons, for example. The spacecraft took about 8000 measurements or photos in it's rendezvous with the Pluto system. It totalled about 6 GB of data that took 15 months to return to earth (with a maximum effective rate of 2kbps). Obviously Saturn is closer, and you could get a better transfer rate, but at some point you hit a limit of how many pictures you can take versus what image quality you can accept.

I'm willing to take those limitations. While Pluto is just Goofy, we could start with the other planets. What would Jupiter's clouds look like? Venus? We receive much more information from the orbiters of these planets, so hopefully on future missions (please let us keep them going) we can get these images. Honestly, I'd be happy to receive a JPEG from a modern DSLR just to save space, but obviously the RAW would be ideal. After all, if we're doing this, let's do it.

Would "any modern camera" be able to withstand a decade of hard vacuum and the high-energy radiation environment of space?

I really like the idea of raw unedited data. The closer we get to captured scientific data the better the feeling of exploring the planet in real life is for me. The whole artistic spirit of realism leaves me a bit flat because it ends up being like Jurassic park dinosaurs - the missing parts filled in with frog DNA and jacked up for theme park amusement. Colours blown out, infinite camera perspectives, musical stings and character plot or gamified systems of interaction.

Exploring raw data is closer to participating in electronic discovery than exploring an artists attempt at making a huge empty planet palatable to the spending consumer.

Depends on what you mean with "raw data", the pictures shown in the post are clearly calibrated data: you can tell because there isn't a lot of noise and other camera artefacts.

Here is an nice example showing how WISE (W3) images go from real raw data to science calibrated images: http://wise2.ipac.caltech.edu/docs/release/allsky/expsup/fig... (taken from http://wise2.ipac.caltech.edu/docs/release/allsky/expsup/sec...)

you totally captured the emotional response I had to these CD-ROM sets... I just wish I'd written it better, but that's just it there.

It was certainly cool to decode the raw stuff myself, although Iv'e been told so many times since I wrote that to either 'enjoy' the artistic version, or get some 'better' version of these things already transmogrified... But I wanted to do it myself!

It really did feel like I was accomplishing something when I got the first image to render, I guess it's the Ikea fallacy? Oh sure any idiot can click on a JPEG but can you follow well documented steps, and use a highly portable program to let you reproduce the same images?

Either way, I had fun doing it, although it feels like I did this a lot longer than a year ago...

For an even more primal experience, it's worth looking at Saturn with your own eye through a telescope. An 8" reflector is fine. Even though it is obviously nothing like these photos, it is surreal to see that object up in the sky.

I had that experience at a charity stargazing night here in Houston not long ago. It's really something!

How discrete are the rings of Saturn? Do they look continuous due to the long exposure time of a photograph? Would they look more like an asteroid belt if we could increase the shutter speed?

Discrete enough to have names of their subdivisions-

https://en.wikipedia.org/wiki/Rings_of_Saturn#Subdivisions_a...

Those are gaps between rings. I'm asking about the rings themselves - would they look more like dotted lines?

>> They consist of countless small particles, ranging in size from micrometers to meters

>> The densest parts of the Saturnian ring system are the A and B Rings,

I don't see anything that says exactly how dense the rings are, though...

I think that when you're close enough to resolve a meter-sized (car-sized) object, the ring would look like a straight band to you. From where you can see the rings curved, you must see them as "solid".

You made me curious. I can’t find any technical information how the pictures were made but I wonder. The rings are between 10m and 1km thick which is pretty thin.

Check here for information about the instruments: https://pds-atmospheres.nmsu.edu/data_and_services/atmospher...

Two days days ago this was on apod: https://apod.nasa.gov/apod/ap200419.html

I really miss having a working APOD official iOS app. The others just don't appeal to me.

That video is gorgeous. "That' no moon!"

PDS Atlas is the best place to get this data: https://pds-imaging.jpl.nasa.gov/search/ and USGS ISIS is the software to work with it: https://github.com/USGS-Astrogeology/ISIS3

This is where I end up if I start at the planetary data archive, these are the raw images for Saturn: https://pds-imaging.jpl.nasa.gov/volumes/voyager.html

The touching up of photos by NASA is really interesting - I don’t want to fuel all of the mars conspiracies but undeniable that a lot of stuff in the mars photos is obviously airbrushed and there has been a transition from everything on mars being red hued to blue sky with lots of greys and browns in the landscape, it shows that NASA has taken a lot of artistic license. The Viking probes all had color calibration plates attached, so I’m pretty sure someone made the decision to tint the photos because “the public expected the red planet to be red”, then someone else made a different decision, so slowly the red hue is being replaced with natural colors just to save face.

I don’t really know anything about astronomy, but I noticed a planet at dawn and looked it up: Jupiter! Saturn and Mars are also super visible in the same part of the sky about an hour before sunrise. Pluto is lined up too but obviously not visible. Have a look!

SkyView was an app recommended to me, but it would be cool to have something a little more scientific. What’s a nerdier app I can’t try?

You could try Stellarium: https://stellarium.org/

It has many features and takes quite a bit of exploring.

Love it, thanks! Specifically:

https://stellarium-web.org/

Sky View is nice but it’s a bit noddy: I couldn’t get it to break down the four big moons of Jupiter, which are so clearly visible, but I didn’t know which was which!

> like all old CD-ROM’s they are not quite ‘ISO CD9660’ enough so they don’t mount on Windows 10, or OS X.

Not sure what the issue was here, I was able to mount the file just fine on my Windows 10 machine

Are you using daemon tools or something else 3rd party?

I couldn't get them to mount on Windows 10, I ended up using MS-DOS to mount them. I've had this issue with a number of early 90's CD-ROM's that apparently violate the spec, including Microsoft Bookshelf

https://archive.org/details/MicrosoftBookshelf1991

No, I just changed the extension to ISO and double clicked, using the native ISO mounting functionality.

Can't test with MS bookshelf as there doesn't appear to be an ISO provided

EDIT: Nonetheless thank you for preparing these interesting images!

Maybe it's been some update or something, it sure didn't work when I tried this a year ago.

I ripped the CD of bookshelf as a MDF

https://archive.org/download/MicrosoftBookshelf1991/msbooksh...

Since it wasn't mounting for me either with the physical disc, or the image... I passed the drive under Qemu and MS-DOS read it fine.

The whole thing was... Strange in that I can't get these old discs to mount. Although they read fine. strange.

It was really fun taking these old CD-ROM's disc images, and actually manipulating the data. I didn't expect to get anything and I was really surprised that it worked.

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