Help - Search - Members - Calendar
Full Version: Mercury Flyby 1
Unmanned Spaceflight.com > Inner Solar System and the Sun > Mercury > Messenger
Pages: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12
JRehling
[...]
tedstryk
For those having trouble downloading it, here it is.

Click to view attachment
Click to view attachment
edstrick
I've finally had time to chew on the approach color image. A first try resulted in progressive loss of color toward the terminator. This is not entirely bad, as the color signal-to-noise ratio goes to hell as brightness levels drop and fringing related to image registration imprefections increase with low-sun-induced contrast. Decolorize it in photoshop and it's probably to some extent a "best rendition" of the approach image. The second used the approach image with limb to terminator gradients removed and colorized it with color data separated out of the raw images separated out as R-B-versions. (Not quite raw, I had to subtract a zero-offset varying from 3 or 4 to 1 from each image to blacken data beyond the terminator.

Behold: The color diversity (in these bands) of Mercury (at least the approach crescent)
DEChengst
new MESSENGER pic of the day:

http://messenger.jhuapl.edu/gallery/scienc...0108830513M.jpg
tedstryk
Fascinating. You can really see how Lava channels cut through the Highland terrain and flooded a multiring crater. Also, there is one of those funny pit craters in the middle of it (not sure if we have seen this one before or note.

I have attached an enchanced version of part of the image, both with arrows to show the channel, flooded crater, and pit crater, as well as a version with no arrows.

Click to view attachment

Click to view attachment
MarcF
Really interesting pictures. I think we'll have to wait untill the 30th to see what I'm really looking for: Caloris !!
Marc.
Stu
Wow...!!!

Just got back from holiday - can recommend Cyprus very highly, tho it tok some used to seeing Mars and Sirius so high in the sky! We saw a great Elvis impersonator on my birthday tho! smile.gif - and catching up with stuff... These latest MESSENGER images are nothing short of stunning, especially when you see them all in one go, like I'm doing now...

BTW, anyone know what happened to the pics archive at:

http://messenger.jhuapl.edu/gallery/sciencePhotos/pics

? There's nothing on that page when I go to it..?
djellison
They've locked that folder on their server I think - to stop the likes of us sneaking a peak of what's coming next.

Doug
Stu
QUOTE (djellison @ Jan 27 2008, 09:07 PM) *
They've locked that folder on their server I think - to stop the likes of us sneaking a peak of what's coming next.


Curses! cool.gif

Oh well, it was good while it lasted; we can't complain I guess. smile.gif
Stu
New Mercury poem up on my poetry blog, if anyone wants a look...

"MESSENGER'S MEMORIES..."
gcecil
QUOTE (Stu @ Jan 28 2008, 09:18 AM) *
New Mercury poem up on my poetry blog, if anyone wants a look...

"MESSENGER'S MEMORIES..."


Don't apologize for Caloris. Based on what I saw at APL, I'm sure that there will be important announcements at the press conference day after tomorrow. In NAC mosaic #2, it is *far* more interesting than it appears in the WAC pictures. I can't say more at this point, but prepare to see amazing detail across the N half of this hemisphere.
Stu
QUOTE (gcecil @ Jan 29 2008, 12:26 AM) *
Don't apologize for Caloris. ... I can't say more at this point, but prepare to see amazing detail across the N half of this hemisphere.


I figured as much, which is exactly why I said in the poem:

In the months and years to come I’ll share with you
a better view, I swear
: Great Caloris will be
a gaping gunshot wound in Mercury’s
furrowed forhead, but ‘til then instead
you’ll know it as a mere memory of mayhem,
an unknown wonder on a solar-wind baked stone…


smile.gif

climber
Just a reminder : NASA TO RELEASE SCIENCE RESULTS AND NEW IMAGES FROM MERCURY FLYBY

WASHINGTON - NASA will hold a press conference at 1 p.m. EST on Wednesday, Jan. 30, to announce scientific findings and release
never-before-seen images of Mercury.
tedstryk
This is beyond cool! They say they are releasing the movie tomorrow.
http://messenger.jhuapl.edu/gallery/scienc...mp;image_id=142
ugordan
Cool. Looks like it might be 2x2 binned, though. 288 full-res frames is a lot after all.
elakdawalla
Cool. Don't forget that there are actually two movies, one inbound and one outbound. The inbound one is three-color, using red, green, and blue filters. My suspicion is that they have not had enough time to make the inbound one pretty yet, so I don't think we'll see it tomorrow (of course I'd be delighted to be wrong), but it does look like they're going to release the outbound one!

By the way, you may have noticed they switched to JPG format from PNG for posting press-released images. This is because there's some problem they're still trying to figure out that caused some visitors to have problems viewing the PNG formatted images. I'm told that once they solve the problem they'll switch back to PNG.

--Emily
tedstryk
I am aware, but it is really exciting to actually see some of the images from the outbound sequence.
belleraphon1
There is no such thing as a boring planet, world, wordlet, rock.... I am certainly no geologist, but as Stu pointed out a few posts back, stones have such stories to tell...... I wonder that we do not wonder over them more often.

And here we have a world alternately seared and frozen over gigyears.... what portents and treasures are sealed across its surface?

Boy.... I am sooooo looking forward to tomorrows press briefing.

The best is yet to come... 2011

Craig
tedstryk
Well, tomorrow is the big day! For now, here is an improved color view from mariner-10 as it sped away from the planet.

Click to view attachment
Stu
TODAY's the Big Day for those of us on this side of the Great Water, my friend! smile.gif I'm off to work now and when I get back there'll be just a few hours to go...! biggrin.gif
edstrick
" you may have noticed they switched to JPG format from PNG for posting press-released images"
I sort-of noticed.
The main thing I've noticed is that they've used SMALL amounts of compression on the images I've enhanced, so I hardly notice compression artifacts if at all after the enhancement work normally would have produced humongous amounts of compression noise.

And tedstryk... thanks for the work on the Mariner color.... I need to get them on the 32 bit processing machine and try my evil tricks on them. May need to get low compression or tif versions for the best result.
tedstryk
Here is a slightly improved version in .png format.


Click to view attachment
ugordan
The press conference has just started. For those not following, here's an appetizer:

Mercury Shows Its True Colors
volcanopele
http://messenger.jhuapl.edu/news_room/stat...t_01_30_08.html

Press release
DEChengst
And we have pictures/movies here:

http://messenger.jhuapl.edu/news_room/multi03.html
elakdawalla
I have to say I'm a bit disappointed with the inbound movie. I tried importing the .mov file to Photoshop so I could pull out their individual frames and maybe make an animated GIF at a lower frame rate, but the frames look pretty cruddy when I do that. They look smoothed and blended and sometimes even interlaced. sad.gif THe outbound one is much better, but its aspect ratio got stretched, making Mercury look like an egg!

--Emily
tedstryk
The aspect ratio seems wrong on the inbound movie. I hope they release better versions. I wouldn't blame them for waiting until the press conference related surge is over before putting it on their website.
mps
QUOTE (ugordan @ Jan 30 2008, 08:01 PM) *
here's an appetizer:

Mercury Shows Its True Colors


but those are not true colors: "The color image shown here was generated by combining the mosaics taken through the WAC filters that transmit light at wavelengths of 1000 nanometers (infrared), 700 nanometers (far red), and 430 nanometers (violet)."

I'd like to see the REAL true colors of Mercury.
djellison
They described it during the conference as, in true colour, being very very much black and white.

Doug
JRehling
[...]
ugordan
QUOTE (mps @ Jan 30 2008, 08:41 PM) *
I'd like to see the REAL true colors of Mercury.

I've made a two-segment linear approximation (with a knee at blue-green wavelength) of the released Mercury spectra, ran it through some CIE XYZ code and this is the (non-gamma-corrected) resulting color:



I took the "green" channel from that color release which approximates red in real color and "blue" which approximates blue (contrast-wise, the channels were equalized in brightness in the official release), created a synthetic green and adjusted the levels by the above result. This is what it ought to appear to human eyes:



This is not gamma-correct, rather a simple lowering of saturation to mimic the 2.2 gamma saturation, while at the same time preserving contrast of features. Gamma-correct look (assuming the team did no contrast manipulations already) can be found here. Very soft colors, reminiscent of some Moon shots, but with a touch more saturation to it. An interesting comparison of the display-correct version to an image of the Moon from Apollo 10: http://www.hq.nasa.gov/office/pao/History/...0-35-5249HR.jpg
If you think the albedo features in the gamma-correct version are too bland, consider the Moon. Take away the maria and you're left with very subtle contrasts as well.

"Natural" color indeed can look less than impressive, but we should be aware how the planets look nevertheless. I get nauseous when I see an orange-red Venus painted with Magellan data. That's pretty much every time it's depicted anywhere, be it a poster, a textbook, a certain JPL site...
MarcF
The "spider" in the center of Caloris reminds me the one found in the center of Mannann'an crater on Europa:
http://photojournal.jpl.nasa.gov/jpegMod/PIA01406_modest.jpg

Was also considered as something never seen before.

Of course, the scale is not the same, the surface material is quite different, but who knows, may be the formation processes are similar.

Marc.
mps
Thanks, ugordan.

I know that true colors images are often less spectacular than false color images, but I always prefer natural colors.
Just like to know, how would it look like trough my own eyes smile.gif
ngunn
QUOTE (mps @ Jan 30 2008, 09:34 PM) *
Thanks, ugordan.


I'd like to echo that, much appreciated - especially since I can't access any of the NASA stuff from home. Until I get to work tomorrow I'm dependent on the ripples produced here by the data release.
Bill Harris
Either there is a stitching artifact running across the middle of Prockter06.jpg or we've got some sort of strike-slip fault...

--Bill
DrShank
looks very much like a standard image offset, not a strike-slip. Im sure people will be looking for them.

here is an stretched version of the color mosaic. all sorts of different colors pop out. looks like 3 to 4 basic units,
including caloris fill, volcanic and impact plains and young crater units. should make interesting mapping . . .

paul
edstrick
Click to view attachmentI ran ratio enhancements of the Proctor7 image and then applied the colors back onto two versions of the bandpass enhanced average of the 3 bands. Here are the results. Caution and warning: There appear to be discrete boundaries in the cratered plains, for example southwest of caloris near the image center. I think these are digitization levels in the color channels of the JPG and not real geologic features.

The "enh-3" image shows the most color and terrain/albedo detail in a balanced fashion.
The "enh-bw-2" image shows the enhanced average of the 3 bands
The "enh-2" image has stronger colors overlaid on the "enh-bw-2" version.

Note various craters and other non-crater features, some in Caloris, some elswhere, that show a distinctive orange-yellow color: south Caloris rim vicinity, a crater N of Caloris, the center only of a crater south of the image center, scraps of terrain WSW of Tolstoj. Some dark albedo features near frame center and crater rims in the south mid latitudes are dark and blue <all colors relative>. The double-ring basin halfway beteween Caloris and the terminator have distinctive light-blue colors in the ring of peaks, as does the large crater to it's SSW with a sharply defined ring of central peaks. There seem to be a LOT of craters with central peaks totally different in color from the rest of the crater: floor, walls, ejecta and surroundings.

Plains filling craters and basins and inter-crater-plains tend to be somewhat higher albedo than adjacent non-plains and somewhat redder: yellowish, tanish, compared with surroundings. It's clear that we're dealing with volcanic fills, rather than impact melt sheets -- the Caloris ejecta is remarkably non-distinctive -- but none or essentially none of them appear to be dark like lunar basalts.

JRehling
[...]
ugordan
QUOTE (JRehling @ Jan 31 2008, 09:01 AM) *
Something in the normalization of the raw data could also be at work.

Residual bias in the CCDs can easily be the culprit, such as incomplete removal of dark current (say due to different camera parameters or different lookup tables used). Another reason might be flatfield effects near the left side of the detector.

The levels of excessive saturation applied seen here will bring out even the tiniest filter-to-filter differences.
Bill Harris
Good work, edstrick. This does highlight important compositional differences in the surface (and subsurface, counting the excavations).

A good reference to the nearest "terrestrial analog" (our Moon) is at Steve Alber's website. Warning: it seems that the data file is corrupted at the site, I can only get some 3mB of te 4.8 mB file and can't view the southern 1/3 of the image.

http://laps.noaa.gov/albers/sos/moon/moon_...olor_brim16.jpg

--Bill
Gladstoner
.
edstrick
They're relatively blue as are the central peaks of the peak-ring, the DARK splotches outside of them are intensely blue. <wavelength-relative> as is the dark area between the peaks. The rest of the crater floor and walls and surroundings are utterly nondescript other than a yellowish tinge to the walls, rim and close-in ejecta.

There are scattered things like this in the Mariner data.... oddities, more seen at high sun than at low sun so relief is uncertain, generally not well seen...
It's been hard to do more with them than scratch dandruff at them.

The dark and blue might be high-titania...... but.. ?basalt?.. nothing dark like basalt seems to be widespread.

Note: These images had to be degraded to get them online here. More jpg artifacts than in the original enhancements.
Bill Harris
>The white splotches

The almost look like alluvial fans. I wonder if the uplifted rock unit of the central peak is not of a composition that weathers to a light-toned deposit?

--Bill
edstrick
I'm going to add two more enhancements, both black and white: the enhanced red and the enhanced blue component of the "enh-2" color version.
The "Super-Red" image largely suppresses low contrast ejecta splatters and turns the brightest, bluest of them black, vastly reducing ejecta interference with underlying terrain differences. the "Super-Blue" image, conversely, nearly eliminates widespread, reginonal albedo and color variations between units, rendering any lighter and bluer ejects with Tycho-Ejecta like-new effect.
edstrick
"I wonder if the Hapke function varies for different wavelengths. The amounts of excess green near the terminator and yellow near the limb seem suspicious. Something in the normalization of the raw data could also be at work"

Yes, and the distinct UV to IR upward slope in the spectrum is the sort of thing that brings out weak photometric color effects, but I doubt that's significant here. As commented above, tiny errors in image calibration can wreck havoc with really strong enhancements like these. 1/2 DN <digital number> can wash your color differences with a color cast near the terminator. I had a horrible red cast near the terminator in the approach image color enhancement I posted a few days ago. There turned out to be 3 DN of scattered light near the terminator on the dark side in the "red" channel, less than 1 in the "blue" channel. Subtracting appropriate zero-level offsets vastly improved the result though it was not perfect.

For quick-and-dirty calibration, i'm NOT complaining. This promises high quality results from carefully calibrated and non-jpg degraded 11 channel data to come.
edstrick
Hrmn.nnn..nn.
I'm trying to compare enhanced colors in the approach vs outbound images and I wonder if I have a color band <green?> swapped in the approach data. Plains are often yellowish in the outbound data, while they're light violet-ish in the approach data to some extent. I'll have to poke at that data some more.
ugordan
You have to realize the MDIS team most likely did channel brightness scaling in both composites for visually more appealing results. The individual channel brightnesses don't match the actual brightness of the filters as can be seen even in the surface spectra. The violet filter is much darker than both longer wavelength views, yet the inbound view is distinctly violet-ish.

To a first order approximation, it appears to me the outbound colors are scaled to get a gray color for the plains. This was the basis for my natural color result earlier, reducing the equalized brightness of the channels to their respective brightness levels based on surface spectra.

The inbound image seems to have an even more brightened up violet channel so results between the two views cannot be directly compared.

As mps said earlier, I don't exactly approve calling that outbound image Mercury's true colors. That's the sort of thing that'll lead to yet another case of what-exactly-does-Venus-look-like debate. Is that the color we want Mercury appearing in all the textbooks in the world from now on?

Sexing up Mercury this way is fine (let's be honest - imagery; sexy, colorful imagery helps sell missions) as long as you don't mislead the public. Never mind if the actual image advisory sets the facts straight, it's often the caption that counts.
SpaceListener
The "Spider crater" located on the floor and near the center of Mercury's giant Caloris basin

After watching the best picture I have ever seen on the giant Caloris Basin. I am trying to figure out how of more than 100 narrow, flat-floored troughs radiating from a complex central region is formed.

I cannot believe that after the impact of an asteroide, it creates balls to roll out from the impact site. I thought that it is typically that after an impact, all debris or rocks flies away from the impacted site but not by rolling. Maybe, it is due to greater gravity of Mercury which has greater tug on the rocks by avoiding its flying path away. No obstant, the other thing I am thinking that the rays might be made by flow of lavas.

Any comments with respect of the origin of rays? smile.gif
ngunn
QUOTE (SpaceListener @ Jan 31 2008, 03:54 PM) *
[Any comments with respect of the origin of rays? smile.gif


Emily mentions some ideas being considered by the science team here:
http://planetary.org/news/2008/0130_MESSEN...by_Reveals.html
JRehling
[...]
This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please click here.
Invision Power Board © 2001-2020 Invision Power Services, Inc.