Oh very nice. How did you make that?

Mapped the latest photo to the vesta model and rendered two images for the anaglyph.

Well, the two bigger ones definitely look contemporaneous, and the way their ejecta airbrushed the surrounding terrain is pretty neat. Can't tell if the head of the snowman was there first or not.

The rim of the third, smaller, crater looks to be more rounded instead of knife-like as the two larger craters do, so I would assume that it is older.

Additional images have appeared on the Framing camera's facebook.

LOOK at that bottom one! There are possible compositional differences within a small geographical area, much like Mercury!

Ooo! Ahhh! Here we go!

GREAAAT idea Emily ! Thanks to you and LEGO, and 15 years after Lou's bright ideas, it's now "Red Rover goes to... Vesta" !!! Thanks a lot for this nice EPO policy for your PS members

Nice images! Thats a very Iapetan-looking ridge trending 'South-West' in the first image.

Man, the things a HiRISE or Cassini NAC would be seeing there at this point...

Just some shameless bragging, here: Pablogm1024 was our guest for dinner last Thursday, and he is indeed most amiable & engaging company! Unfortunately, we couldn't find the camera (Mrs. nprev had misplaced it!), and I'm therefore quite sorry there's no pic to post. But it was quite a time!

I would be remiss if I did not mention that the inimitable & brilliant Juramike also stopped by a couple of weeks ago as well. I will post a pic if anyone wants to see it, and if Mike consents!

Hmmm, we're still a fair way away, but do I see some lobate flow features outside the rim of the lower torso of the snowman? That's also one HUGE boulder that seems to be sitting on what passes for a central peak! Finally, is it just me (or the lighting angles) but does the lower torso look sharper edged (and younger) than the upper torso?

P

I think there's one new image here:
http://dawn.jpl.nasa.gov/multimedia/dawn_v...e_365886460.asp

The crater rim center top reminds me of old space art, with the ridiculous fumarole-like craters.

Overlay of PIA14671 and PIA14325 (false-color filtered image of the higher resolution bright splats on Vesta):

Click to view attachment

Two of six faces more or less complete. But I'm running out of 1x1 and 1x3 plates; the other 4 faces might have a little bit coarser resolution, or maybe a different color

Click to view attachment
(Cross-eyed stereo)

Future Astronomy reporter?!

Great model! My 7yr son approves!

Awww...

That looks ubercool thus far, Emily; thanks for a glimpse of the work in progress!

Re colors: Might be cool to do a topographical corolation with them of some sort, if that's at all feasible. The resolution of the model seems to be a couple square km per block or so..

Using two of the recent images of the snowman, I created a quickie anaglyph.

Click to view attachment

And it all started as a joke...

Cool!



Nice! It's interesting, that we still haven't true color images, only these with enhanced colors.

The first press release after orbit insertion showed a color image from the imaging spectrometer that showed apparently visible wavelengths. It was completely white/gray with no visible color variation. I don't know if they normalized the reflectance to Vesta's average spectrum to get that, but even if they did, Vesta's actual color judging from Hubble data is very bland. I posted a colorized grayscale using Hubble 2-filter color data here, that should give you a rough idea on color intensity.

Dawn's south polar region (from July 24, 2011)

http://www.nasa.gov/mission_pages/dawn/mul...a/pia14322.html

Click to view attachment

Yes, Guillermo

I was in vacation and now I can write on forum.

That image was released 2 weeks ago -- why post it now? Was there something about it you wanted to discuss?

I just noticed an oddity about how the Dawn images are posted. As usual, the punch line is: for the best quality version of an image, do not pass "Go," go to Photojournal and grab the TIFF.

Photojournal always has both TIFF and JPEG versions of an image. In rare, horrible cases, the TIFF has been made from a JPEG, but in most cases (including, as far as I can tell, Dawn), the TIFF is made from a file that was provided to the webmaster in some uncompressed format, and the lossily compressed JPEG made from that.

The NASA.gov website for Dawn is rarely updated with new image releases, so don't even bother going there.

As for the JPL Dawn website, you have to watch what you click on because there are a couple of different versions of each image. Go to the Image of the Day gallery and you'll see a bunch of thumbnails with brief captions. DO NOT CLICK ON THE THUMBNAILS. They take you to versions of the images that have been resampled to 700 pixels across, regardless of their initial size. Click instead on the "Full Image and Caption" link and then on the "Full Image and Caption" page go to the "Download Image > Full Size" link. The 700-pixel versions are the ones displayed on the "Full Image and Caption" page; they don't represent the original-res data. And they may even have been JPEG-compressed twice (once to make the "full size" JPEG, and again when saved as the 700-pixel version), but I'm not sure about that.

Or, like I said, just use Photojournal!

Will all the "images of the day" be going to Photojournal?

Indeed - I wasn't paying sufficient attention to the date when I posted it. Mea culpa.

I know for a fact that for Dawn, Photojournal TIFF images have been converted from JPEG. At least some, possibly not all.

I am not so sure this only rarely happens.

Well, shoot. That's stinky. But thank you very much for clearing that up. I guess the question then is where to get the least JPEGged images. I would assume that's still Photojournal.

I've always wondered about this as well. One would assume that the spacecraft beams the images to earth in JPEG format, with at least a little compression rendered on the original, considering the bandwidth limitations. TIFF images take up many more kilobytes than JPEG, so I would be very surprised if TIFF images are generated on the spacecraft for transmitting to Earth.

Spacecraft transmit neither JPEG nor TIFF format down to Earth. Actual telemetry format of the files will look nothing like computer formats we use here on the ground. Depending on the lossy compression scheme used on the spacecraft the algorithm can be pretty close to JPEG, though. However, not all data has to be returned losslessly compressed.

In short, the formats Photojournal uses have nothing to do with what spacecraft use.

It has been my personal belief ,for the last 10 years, that jpeg should be illegal

it was good in replacing the 8 bit indexed gif back in the 90's and was good for 24k dial-up

I was hoping it would get replaced by jpeg2000 and dispose of those blocking artifacts, but alas it was not to be.

Anyway, we digress...

For the record, I always send along PNGs when I have any product that would go into the Planetary Photojournal.

PNG FTW!

we could remove them
for image "PIA14673.jpg" the tiff is good
before
Click to view attachment
after
Click to view attachment

gmic dose a good job, though some detail is lost .

QFT.

New image release today has some more false-color fun!

http://photojournal.jpl.nasa.gov/catalog/PIA14677

Hokay, played with this. Red and blue are 750 to 450 and 450 to 750. So took those two channels and created a grayscale image of each then overlayed them at 50%. Whaddya know, they come out almost to a bland 128 pixel blandness. Put both of those in red and blue channels. Then put the green channel of PIA14677 back in.

Green channel is 750 to 950 nm ratio. Fe absorbs at 1000 um. So Hi Fe will have a "Hi" ratio (bright).

(Overaly HiPass filtered image for details, adjust green channel gamma and...)

Et voila, a map of Fe minerals: Iron-O-Vision:

Click to view attachment


Green is Fe enriched, magenta is Fe depleted.

If I'm gonna guess, in this region there is a thin layer of Fe-enriched material. Mid-size recent craters dig this up and splat it on the surface as ejecta.

Bigger craters dig much deeper into an Fe-depleted layer and this lands on top of the other ejecta close to the crater. So the larger craters have an inner ejecta ring of Fe-depleted material (magenta) inside the Fe-enriched material. The uppermost poofy dust layer seems to be Fe-depleted. The landslides inside the crater also seem to be Fe-depleted (magenta).

Just my guess....

Oooo, and notice how some of the craters in the lower part of the image have a touch of green at the center, but craters bigger than this don't. Those correspond to about 11 pixels, (x 450 m pixel) so, 5.3 km crater. Maybe indicating the Fe-rich layer is maybe only 4-5 km below the surface?

wow! Up and Down in Vesta's Cratered Terrain

Our first good look at the northern hemisphere, if I'm interpreting it right. Very ancient looking.

Visually very similar - Phoebe v Vesta

False-color coordinated image released by the Dawn spacecraft team today as PIA14680.

Click to view attachment

So...shallow fresh craters make visually bright (false-color yellow) stuff (iron-rich material), will deep craters dredge up dark (false-color orange) iron-poor material.

What is the really-dark false-color blue stuff? Melted iron-poor stuff in cracks and fractures or iron-poor poofy dust?

Poofy dust? (not that there's anything wrong with that)

Phil

Is the dark, blue-purple color due to some spectral signature, or is it the effect that a darkish to nearly black material has on the false-color scheme?

Or both?

Or something else altogether?

FWIW, 'poofy dust' has my vote.

It is definitely darker in the "normal" grayscale image (clear filtered image? centered at wavelength...?) So it is low albedo.

From the description of the false color image since it is "brightest" in blue wavelengths, it means that:
the ratio of 750 nm to 450 nm is v. low (dark in red channel of the false color image)
the ratio of 950 nm to 750 nm is v. low (dark in green channel of false color image thus iron poor (iron absorbance at 1000 nm)
the ratio of 450 nm to 750 nm is relatively highest, (brighter in blue channel of the false color image)

So it is a "dark blue rock", or at least not as much visible red as the other rocks. No clue by how much the ratio is. The rock might appear only dark bluish even if you totally jacked up the saturation of a normal photograph.

'Course this could also be a grain size effect. I'm trying to remember if smaller grains are generally bluer or redder given the same composition. Help?

Well, this is just lovely...

Small grains of reddish materials (i.e. most rocks) should be less red than larger grains, because the smaller particles scatter more and absorb less. The reverse is true for bluish materials such as water ice- smaller grains (snow) look less blue than larger grains (big chunks of ice).

John

This latest image of the south polar central mound is really cool-looking but I just don't know what to make of all of the different ridgy textures at all different scales. Any geologists out there want to try some arm-waving?