Color Images from Mars Rovers
by Bob Webster
Thanks to Bob Webster for making these images available. They are recombinations of images with different colored filters. All images are courtesy of NASA/JPL and in the public domain in the United States.
Mars Attacks!
I was browsing the NASA web site for photos from the Mars rovers, but most of them are black and white. Then I noticed they have the raw images posted that can be combined into color photos, so I combined a bunch of them into "living color." Here they are:
Mars in Color, from “Opportunity” Opportunity Photos Mars in Color, from “Spirit” Spirit Photos
The color is not perfect on these, but it should be in the neighborhood. There are a lot of variables. The cameras are calibrated differently from time to time, there are different bandwidths available in different images, and the sun is at different angles.
In these photos, 3 to 6 images were taken, one after another, using different bandwidth filters. There may be 5 minutes pass from the first to the last image, so a shadow may move a little bit during that time. An interesting effect of this is an occasional rainbow strip on the edge of shadows.
The image file names include information such as camera type, time taken, location, etc. Here is the full info:
http://origin.mars5.jpl.nasa.gov/gallery/edr_filename_key.html
The image on this site have the filter and sometimes the Left or Right designator removed. If L or R is missing, then they were taken with the Left camera, which uses visible light filters.
These images were taken with the panoramic camera, because it's the one that uses color filters. The filters used vary from image to image. The available filters are:
Left Camera Right Camera
1 = EMPTY (clear) 1 = 436nm (37nm Short-pass)
2 = 753nm (20nm bandpass) 2 = 754nm (20nm bandpass)
3 = 673nm (16nm bandpass) 3 = 803nm (20nm bandpass)
4 = 601nm (17nm bandpass) 4 = 864nm (17nm bandpass)
5 = 535nm (20nm bandpass) 5 = 904nm (26nm bandpass)
6 = 482nm (25nm bandpass) 6 = 934nm (25nm bandpass)
7 = 432nm (32nm Short-pass) 7 = 1009nm (38nm Long-pass)
8 = 440nm (20) Solar ND 5.0 8 = 880nm (20) Solar ND 5.0
Some bandwidths of visible light are:
red 650
orange 590
yellow 570
green 510
blue 475
indigo 445
violet 400
Everything gets kind of fuzzy from this point on. The visible light bandwidths are not even sharply delimited. The bandwidths in the Martian cameras don't necessarily match the color bandwidths on Earthling computers. In a lot of the images some of the bandwidths are missing. For example, this image:
only uses filters 4, 5, and 7, which more or less correspond to reddish-orange, yellow-green, and violet. There is a hole or two in the spectrum, notably red and blue, so it ends up looking a little weird. But it's still much better than black and white.
Some of the images from Mars use filters 2, 5, and 7, or some wide range like that. This provides more information for scientific analysis, but it doesn't look normal when combined. That is, if there is a "normal" for pictures from Mars. I skipped most of these.
The right pan camera filters are mainly longer wavelength in the ultraviolet range. I only included one of those pictures, mostly because I wondered what it would look like:
I used Photo Mud to merge the separate images. In fact, I wrote the Merge Color Separation function in Photo Mud so I could do this. You can download a test version here:
http://xpda.com/photomudsetup.exe
When Photo Mud version 3.0 is released in a few days, I'll replace this file with a 30-day trial version. If you download the test version before then, you can have a free update to the release version without a 30-day limit. Let me know if you find any "design considerations" or other things that don't work.
Here's where to get the latest raw images from Mars:
http://origin.mars5.jpl.nasa.gov/gallery/all
Some of the NASA pictures show mainly red on Mars, such as this panorama:
But the colors in the corners of this sundial in the base of the photo from looks quite a bit different on earth than on the landscape photo. There is a lack of blue in the Mars photo, or maybe even a translation of blue to red. There's probably a good reason for this, since NASA has better software and spent more time on it.
It looks to me like NASA included filter 2, infrared light, in their red color composition. In this image with filter 2, you can see how bright the lower right color tab is:
This one is filter 3, is visible red. The blue tab in the lower right is not nearly as bright:
Here is a composition I did using infrared as red, and shifting the colors toward that end of the spectrum. This is kind of like the sundial in the color landscape.
Here's the image with "normal color" composition:
The second one looks a lot closer to the original photo above. In these two images, the background dirt looks about the same, but these settings make a big difference sometimes.
Photos Courtesy NASA/JPL-Caltech
Mars in Color, from “Opportunity”
4/9/2004
4/8/2004
4/7/2004
4/6/2004
4/5/2004
4/5/2004
4/4/2004
4/4/2004
4/4/2004
4/3/2004
3/30/2004
3/28/2004
3/28/2004
3/27/2004
3/24/2004
3/23/2004
3/22/2004
3/22/2004
3/21/2004
Infrared used for red 3/20/2004
filter 2 (infrared) used for red 3/20/2004
filter 2 (infrared) used for red 3/20/2004
3/20/2004
3/20/2004
3/20/2004
3/19/2004
3/18/2004
3/18/2004
3/17/2004
3/17/2004
Dubbed "Carousel," the rock in this image was the target of the Mars Exploration Rover Opportunity science team's outcrop "scuff test." On sol 51 (March 15, 2004), Opportunity slowly rotated its left front wheel on the rock, abrading it in the same way that geology students use a scratch test to determine the hardness of minerals. The image on the right, taken by the rover's navigation camera on sol 51, shows the rock post-scuff. In this image, it is apparent that Opportunity scratched the surface of "Carousel" and deposited dirt that it was carrying in its wheel rims. 3/16/2004
3/16/2004
3/15/2004
3/15/2004
"Shoemaker's Patio" near the Mars Exploration Rover Opportunity's landing site, shows finely layered sediments, which have been accentuated by erosion. The sphere-like grains or "blueberries" distributed throughout the outcrop can be seen lining up with individual layers. This observation indicates that the spherules are geologic features called concretions, which form in pre-existing wet sediments. Other sphere-like grains, such as impact spherules or volcanic lapilli (fragments of material between 2 and 64 millimeters or .08 and 2.5 inches in maximum dimension that are ejected from a volcano) are thought to be deposited with sediments and thus would form layers distinct from those of the rocks. This image was captured by the rover's panoramic camera on the 50th martian day, or sol, of the mission. 3/15/2004
3/14/2004
3/14/2004
This image is of the exceptional rock called "Berry Bowl" in the "Eagle Crater" outcrop. The study of this "blueberry-strewn" area and the identification of hematite as the major iron-bearing element within these sphere-like grains helped scientists confirm their hypothesis that the hematite in these martian spherules was deposited in water. To separately analyze the mineralogical content of three main features within this area -- blueberries, dust and rock -- it was important that the rock abrasion tool's brush was able to rest on a relatively berry-free spot. The rock's small size and crowd of berries made the 10-minute brushing a challenge to plan and execute. The successful brushing on the target whimsically referred to as "Near Empty" on the rover's 48th sol on Mars left a dust-free impression for subsequent examination by the rover's spectrometers. No grinding was necessary on the rock because spectral data obtained on the dust-free surface were sufficient to verify that the rock's chemical composition differs significantly from the hematite-rich berries. 3/13/2004
3/13/2004
3/12/2004
3/12/2004
The sphere-like grains or "blueberries" distributed throughout the outcrop can be seen lining up with individual layers. This observation indicates that the spherules are geologic features called concretions, which form in pre-existing wet sediments. Other sphere-like grains, such as impact spherules or volcanic lapilli (fragments of material between 2 and 64 millimeters or .08 and 2.5 inches in maximum dimension that are ejected from a volcano) are thought to be deposited with sediments and thus would form layers distinct from those of the rocks. 3/11/2004
3/11/2004
3/11/2004
the 3.1 millimeter-deep (just over one-tenth of an inch) hole ground by the Mars Exploration Rover Opportunity's rock abrasion tool in the target called "Mojo 2" on "Flatrock" was taken on the 44th martian day, or sol, of the mission. It will help complete the chemical analysis of the lowest layer of the outcrop in the crater where the rover now resides. After a brief brushing on sol 45, the science team plans to place Opportunity's spectrometers on the hole to collect data vital to their understanding of this impressive outcrop. Scientists believe that the spherule or "blueberry" in the upper right area of the circular impression was sliced in half by the rock abrasion tool. "Blueberries" are a known obstruction to the grinding tool that cause it to terminate its sequence. Despite the stall, the rock abrasion tool abraded "Flatrock" for one hour and five minutes, producing a cavity ripe for investigation. 3/10/2004