August 7, 2012
We’re used to seeing crystal-clear, high-resolution images from Mars. Various orbiting, stationary and roving spacecraft have been funneling them to Earth for years. We’ve been privy to global photographic maps of the planet, vast panoramas of crater walls, images of dust devils snaking across the landscape, close-ups of spherical hematite concretions, and everything in between. And so to the untrained eye, the photos Curiosity has offered up so far are, frankly, a bit of a disappointment.
Not so to the scientists, engineers and team managers working on MSL. They’re ecstatic. Sometimes they’re so choked up they can barely finish their sentences.
For example, John Grotzinger, MSL project scientist, referred to the very first photo sent back by Curiosity, a blurry mess that would be embarrassed hanging in a modern art museum, as “the best picture of Mars I’ve ever seen.”
And Ken Edgett of Malin Space Science Systems, the principal investigator for Curiosity’s MAHLI camera, when introducing MAHLI’s first image at a press briefing on Tuesday, an image that was essentially a test of the camera’s ability to focus, was practically in tears. (More on MAHLI and the image in a minute.)
So while we wait for better images to come down the pipe – they’ll get here, but it may take a while; Curiosity has to give itself a thorough health checkup first - let’s take a look at just what’s gotten the MSL team so excited.
Our photo tour starts with an image taken not by Curiosity, but rather of Curiosity, as it descended through the martian atmosphere.
Curiosity descends toward Gale Crater. Credit: NASA/JPL-Caltech/Univ. of Arizona
This image was captured by the HiRISE camera on NASA’s Mars Reconnaissance Orbiter (MRO). In the upper left, MSL’s parachute, and hanging below it, its descent stage, are visible. In the lower right, MSL’s heat shield, which has just been jettisoned, can be seen hurtling toward the surface.
This was not an easy shot to get. MRO was 211 miles (340 kilometers) away from MSL at the time, and traveling fast. MRO circles the Red Planet every two hours.
The second image in our gallery is also of MSL’s heat shield.
MSL’s heat shield drops away from the spacecraft during its descent. Credit: NASA/JPL-Caltech/MSSS
This color image was taken by MARDI (Mars Descent Imager), a camera mounted on Curiosity’s underbelly, designed primarily to capture images during the spacecraft’s descent through the atmosphere. In this image, taken two and a half minutes before touchdown, the heat shield has just been jettisoned and is about 50 feet (16 meters) below the spacecraft.
The image shown here is a compressed thumbnail. Higher-resolution versions of this and all the other images captured by MARDI will be sent back to Earth over the next several months. An animated sequence of MARDI images is viewable here. [http://www.youtube.com/watch?v=UcGMDXy-Y1I&feature=related].
Our next image also appears courtesy of HiRISE. This one shows Curiosity on the ground. But not just Curiosity. Also visible are the spacecraft’s heat shield, its parachute and back shell, and its descent stage, which formed the upper part of the sky crane that delivered Curiosity to the martian surface.
MRO captures bits and pieces of the MSL spacecraft scattered about in Gale Crater. Credit: NASA/JPL-Caltech/Univ. of Arizona
Dark spots surrounding the various components of the spacecraft show the darker underlying material revealed by the removal of surface dust. The patch around Curiosity was created by the descent-stage thrusters blowing the dust away as Curiosity neared the surface. The dark spots around the other components were caused by impact as they slammed, like tiny meteorites, into the surface.
Also notable in this image – geologists on the science team are salivating over this – are three distinct geologic regions, which meet at a point to the east and slight south of Curiosity’s landing spot. The distinctly different appearance of the surface in these three regions means they were formed by different geological processes. It’s as though three different chapters of martian history were sitting, a mere 400 meters from Curiosity, waiting to be read by the rover’s array of scientific instruments. Curiosity has a virtual geologic wonderland to explore, right in its own back yard.
Now we get to the fuzzy stuff. First up, the first image Curiosity sent back to Earth, taken just minutes after landing.
Curiosity’s first image, from the ground, of Gale Crater. Credit: NASA/JPL-Caltech
Okay, I cheated. The actual first image was that tiny smudge of a thumbnail, a mere 64 x 64 pixels, inset into the lower left of the larger image. People went nuts when they saw this thumbnail pop up on the screens in the control room at JPL Sunday night. But to be fair, it wasn’t because it was a particularly compelling image, but rather because it meant that Curiosity was on Mars and doing what it was supposed to be doing.
Both the inset image and the larger image (the latter of which is one of the first, but not the first; and full-resolution rather than compressed; and straightened out to correct for fisheye-lens distortion; and upsampled; and processed by the image wizards at JPL to pull out details not immediately visible in the raw image) were taken by Curiosity’s rear Hazard Avoidance Cameras (Hazcams).
The rover has two Hazcams in front and two in the rear, set low to the ground. Their primary job during the mission will be to look ahead (and behind), capturing images in stereo to help JPL’s rover drivers, the folks responsible for commanding the rover’s path, avoid obstacles that might cause it to get stuck. But they also provide a good close-up view of the nearby terrain. For example, visible in the foreground in this image (although the lens-distortion correction creates a false impression otherwise), is a vast field of uniform-sized pebbles. Geologists are already scratching their heads over that one.
Also visible in this image, off in the distance, is the northern rim of Gale Crater. It’s the medium gray wedge in the upper right. In the lower right of the image is one of Curiosity’s wheels.
Mars is a dusty place. And when Curiosity landed, in a blaze of glory courtesy of its descent stage thrusters, it kicked up a lot of that dust. Which is why it’s a good thing the rover’s Hazcams had dust covers.
This next image is not a stereo pair, so for those of you old enough to know what I’m talking about, don’t go drag your Stereopticon out of that trunk in the attic.
On the left, a front Hazcam image before the dust cover was removed; on the right, after. Credit: NASA/JPL-Caltech
Both of these images were taken by one of Curiosity’s front Hazcams. The one on the left is a low-resolution image taken before the Hazcam dust covers were popped off. The one on the right is a high-resolution version of the same view, taken some time later, post-dust-cover-removal. The dust covers appear to have been money well spent.
The most exciting feature in these images is Mount Sharp, a three-mile-high mountain that is a primary scientific target of the MSL mission. It’s the white triangular shape in the upper right of the images, brightly lit by the late-afternoon sun. The dark line at its base is a dune field. It will probably be a year before Curiosity arrives at the base of Mount Sharp. Also visible in this image: Curiosity’s shadow. (It’s okay to think this is very cool. Everybody becomes a nerd for a few days when a new rover lands on Mars.) And a zillion more uniform-sized pebbles.
And finally we get to the first color image taken by Curiosity from its landing site. It, too, alas, was captured through a dust cover.
The first image taken by Curiosity’s MAHLI camera. Credit: NASA/JPL-Caltech/MSSS
The actual image, captured by Curiosity’s MAHLI (Mars Hand Lens Imager) is the inset in the upper right. What the larger composite image shows is the MAHLI image superimposed over a computer-generated digital elevation model of Gale Crater. The data for this computer model was collected by instruments aboard NASA’s MRO and ESA’s Mars Express.
MAHLI’s prime function on MSL will be to take close-up images of rocks and soil; it is Curiosity’s equivalent of a geologist’s hand lens. It will also used to perform diagnostic functions. Because MAHLI is mounted on the end of Curiosity’s robotic arm, it can be positioned to look back at, and even underneath, the rover. The robotic arm is still in its stowed position, but MAHLI’s orientation enabled it to peek out from the side of the rover and snap a picture.
This image, too, shows the distant northern rim of Gale Crater. To view a higher-resolution version of the MAHLI image, click here. [http://mars.jpl.nasa.gov/msl/multimedia/images/?ImageID=4282]
There are other cameras, really good cameras, on Curiosity as well. They will be deployed, and they too will send back their first images, in the coming days. Many of these early images will low-resolution thumbnails. During Curiosity’s checkout phase, the priority is to make sure everything works. Thumbnails confirm that. But higher-resolution images will follow. And they will be spectacular.
NASA updates its Curiosity image libraries frequently. For Curiosity’s greatest hits, go here. [http://mars.jpl.nasa.gov/msl/multimedia/images/] If you like poring over raw images, check out this site. [http://mars.jpl.nasa.gov/msl/multimedia/raw/]