of no fixed subtitle
November 30, 2004
God bless those fine folks at JPL...this is my first FPP, BTW.
is it o.k.?
17 years ago
Just kidding. I enjoy the picture.
I'm surprised to see those bluish colors... Saturn has always appeared pale yellow to me through the telescope. The article explained it a bit but I'm still not sure why that blue northern hemisphere never comes into view.
The blue color is from the scattering of light off the particles in the rings, as well as some of the sunlight "shining" through the rings in the shadows. The northern hemisphere is that same dusty-yellow when the sun shines right on it. We also don't get to see saturn from that angle from here.
OK?!? Hell, it's awesome! My first view of Saturn through a telescope (at about age 20) is easily one of my ten best moments of my life. It was a 'shiver moment.' Thanks!
Well if the camera on casinni is anything like the the one in the
I wouldn't trust those colours.
Actually, schadenfreude, the camera just used simple red/green/blue filters for the image. The imager on Cassini is quite different from that of Hubble for a whole host of reasons, not least of which is that the Hubble does astronomical duty in wavelengths beyond visible light (in both directions). If you were sitting where Cassini was when the photo was taken, it almost certainly wouldn't look to your eye the same as it does on the image. But that's got less to do with any enhancement of the image as it does with fairly typical camera artifacts like exposure time, focal length, depth of field, and lens shape. I know it won't look identical, but I'd wager it would look fairly close to the image sexyrobot linked to.
I just read an article in Discover that explains that the color spectrum for the pictures on Mars is probably pretty messed up. For example, there are whitish blue skies on Mars instead of red, and browny-yellow ground. (I tried to link to the article, but you have to be a subscriber. Sorry!) One of the reasons the article gives for the color shift is that scientists tend to use the ultraviolet spectrum cameras more often, because they are more useful to them.
That is gorgeous. Thanks, sexy.
...whitish blue skies on Mars...
Friendlier sounding than expected.
Quite marvelous vista,
I'd rather see the rings of Uranus...
i want to live on a planet with rings.
Thanks sexyrobot - that made my day.
ahhhhhh, so beautiful.
Only six weeks to splashdown, or crunchdown, or whatever it finds.
actually, chimaera, the cassini does its duty in many many wavelengths as well...the best article i've found on the camera system is
...however it's in german...and i have no idea where this guy got his info...(and i've seen almost all the stuff jpl sent to congress for funding and scoured the web extensively) the best parts of the article (once you translate it...fun!) are the descriptions of how a ccd chip (normally only sensitive to visible and infrared) sees in the ultraviolet (they coat it with glow in the dark stuff and IT picks up the uv and converts it to natural light...pretty sneaky,sis) and the table of what all the filters are and what wavelengths they pass....very handy for figuring out what all the 'raw' images on the cassini site are....since the filter and the date are all the description they post and meridethea, yeah, the colors are all kindsa different depending on what image you're looking at...they process them all different ways to get the most info...or just to look good for their 'press' images...but you can often find pix that are pretty darn accurate...they use a color calibration tool (like a target with color bars...and sometimes even a sundial) on every probe they send to mars...somewhere on the body of the probe where the cameras can turn and look at it...there are THOUSANDS of these pix on file at nasa and they are VERY boring...that's why, when the english designed their beagle 2 probe (which crashed) they had Damien Hirst design their calibration tool...it looked like one of his famous dot paintings...i guess the thing to remember when looking at pix of mars is that it's a lot dimmer there.... about a 1/4th as bright as here.... I've been following the cassini since well before its launch, and it is, simply put, the BEST deep space probe ever built, and the only one sent beyond mars to function PERFECTLY...every instrument...it's spooky how well that thing works...It's probably the only thing out there that makes me proud to be human right now...um...or built by them, anyway :-) if you have any ?'s, feel free to ask...I love to answer...ad nauseum ps i just found (well, ok, back in june) a "cassini launch team" tshirt...complete with pic of the whole thing on the back...at the thrift store for $2! i wear it far too often... now how's THAT for geeking furiously, goetter
*frantically scuttles to thrift store*
what one aches for is the mosaic music makes in one's ears __ Denise Levertov
what we asked for a thousand million stars deep yes, I tell you I've counted them all the oily feel of zeroes slipping through my hands with just so many allotted to each palmful of lightshot night
The picture is wonderful, and so is beeswacky's poem. Kudos all around.
Bees: You amaze me always. Sexyrobot: I be jealous of your shirt. I need to go to bed now and dream of Saturn's rings.