Astronomy Picture of the Day 01-07-04

Explanation: Rocks are strewn across the broad, flat Gusev crater floor in this sharp color picture from NASA's Spirit rover. Recorded by the rover's panoramic camera, the picture is part of Spirit's first color image of Mars - the highest resolution picture yet taken on the surface of another planet. Already revealing alluring and perplexing details of an apparently windswept plane thought to be an ancient lake bed, this stunning view represents only a small fraction of the color image data mission scientists expect to be transmitted in the coming days. As the robotic Spirit rover is preparing to stand up, roll off the lander, and explore the geology of the crater floor, NASA has announced plans to rename the landing site the Columbia Memorial Station in honor of the astronauts lost in the Columbia space shuttle accident.

The thread with the first FR posting of this image (plus the hi-res version) is here:

First colour image from Mars (Spirit) rover is up!

Plaque on Spirit Honors Columbia Astronauts
Jan. 6, 2004

Windtails Show Direction of Martian Winds

A plaque commemorating the astronauts who died in the tragic accident of the Space Shuttle Columbia
is mounted on the back of the Mars Exploration Rover Spirit's high-gain antenna.
The plaque was designed by Mars Exploration Rover engineers.
The astronauts are also honored by the new name of the rover landing site,
the Columbia Memorial Station. This image was taken by the navigation camera on Spirit.

Image credit: NASA/JPL

First color image from Spirit rover thrills scientists
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: January 6, 2004

The sharpest picture ever taken on the surface of Mars was unveiled today, a remarkably detailed color mosaic showing the rock-strewn vista directly in front of the Spirit rover that stretches all the way to misty mesas and hills on the distant horizon.

This is the first color image of Mars taken by the panoramic camera on the Mars Exploration Rover Spirit. It is the highest resolution image ever taken on the surface of another planet. Credit: NASA/JPL/Cornell University

Project managers were ecstatic with the initial results from Spirit's Panoramic Camera, or pancam, a stereo camera system that will give scientists an unprecedented view of the red planet's surface in the weeks and months ahead.

The image released today was merely a slice of the wrap-around panoramic views expected to be downlinked over the next few days. But it as more than enough to whet the scientific appetite of the rover team.

"We're seeing a panoramic mosaic of four pancam images high by three wide," said camera designer Jim Bell of Cornell University, showing off the first color picture from the pancam. "There are actually 12 million pixels in this image, it's 4,000 high by 3,000 wide, and showing it like this is spectacular, you get this kind of grand vista. But it doesn't do it justice. To really do it justice, you have to start zooming in and looking at it very closely and exploring all the incredible detail that's in this image."

He then did just that, narrating a sort of digital flight through the scene, zooming in to show the sort of detail on the surface a human astronaut with 20-20 vision would see while walking about.

"It's approximately the color you would see with your eyes if you were standing there," Bell said. "The resolution , of course, is pretty much the resolution you would see. Pancam has 20-20 vision, it's three to four times better than any previous mission that's gone to Mars.

"In fact, these pictures are the highest-resolution, highest-detail pictures of Mars ever obtained. They are absolutely spectacular. You're getting a glimpse into the kind of detail that we're seeing at just this one part of the landing site. We're looking at one little wedge in front of the rover. We've still got the entire terrain all the way around to build up around us at this kind of resolution."

The smooth surfaces of angular and rounded rocks seen in this image of the martian terrain may be the result of wind-polishing debris, scientists say. The pictue was taken by the panoramic camera on the Mars Exploration Rover Spirit. Credit: NASA/JPL/Cornell University

Narrating the digital flight across the so-called pancam "postcard" image, Bell pointed out features that simply didn't show up in earlier, low-resolution black-and-white images from Spirit's navigation cameras. Those images, stitched together into digital stereo mosaics, were captured at 64 times less resolution than the best images from the pancam.

"As we're panning through," Bell said, "you'll see many small rocks that we couldn't see in that navcam mosaic, many different sizes and shapes. Here's another (depression) like Sleepy Hollow that seems to be devoid of many rocks. These kinds of areas seem to be all around the landing site.

"We're going to keep panning down, we're getting closer and closer to the rover now, the resolution is getting higher and higher, the rocks that we can see in exquisite detail, many of them have (wind-blown dust) tails behind them, you can start to see some features on the rocks," Bell said. "We're going to zoom down ... it's a wonderful mix of both smooth and angular rocks at the landing site and this is obviously something we're trying to puzzle out scientifically. Here you see one of the freshest rocks at the site, it's only a few tens of centimeters across, a relatively small rock, but it has some pits in it. Are they vesicles, are they volcanic features, is it a sedimentary rock, is it a metamorphic rock? These are the sort of questions we'll be asking about the coming weeks."

He then zoomed in on soil near the rover that was compressed and disturbed by the retraction of the lander's impact-absorbing airbags. The soil shows an unusual cohesiveness that defies immediate explanation. It looks almost as if the grains making up the soil just below the surface are somehow stuck together like mud.

This image shows marks in the martian soil (upper right) made by the Mars Exploration Rover Spirit's airbags during their final deflation and retraction. The picture was taken by the panoramic camera on the rover. Credit: NASA/JPL/Cornell University

"Now we're going to pan over to the lower part of the mosaic and you'll see some scratch marks from where the airbags were retracted and there are places where rocks were actually dragged through the soil and the soil was kind of stripped up and folded in some places in very interesting and quite alien textures, in fact," Bell said. "They look very interesting to us and we're trying to figure out what it means for the physical properties of this material. I think trenching into this stuff is going to be an absolute blast once we get the rover down onto the surface."

Principal investigator Steve Squyres, also of Cornell, agreed and said "we're going to have a real interesting time trying to figure this stuff out."

"The way in which this surface has responded to the retraction, the dragging of airbags across this, is bizarre," he said. "I don't understand it, I don't know anybody on my team who understands it, but we're dying to get a closeup view of this spot."

Pressed by a reporter, he agreed "it looks like mud, but it can't be mud. I can't say much more about it than that at this point. It is very cohesive, it holds together well, it sort of looks like when you scrunch it, it folds up and that's not like most materials I can imagine being on Mars. I don't know what it is."

As for the distribution of rocks at Spirit's Gusev Crater landing site, Squyres would not speculate about source or composition. Scientists believe Gusev once harbored a vast lake, fed by a 500-mile-long channel entering from the south. But Squyres said it's too early to draw any conclusions from the rock distribution at the landing site or the gross appearance of the countless stones.

"For the most part, I would still say the rock distribution at this site is markedly different from anything that we've seen at any other landing sites on Mars," he said. "Compared to either of the Viking sites or to Pathfinder, without question there are far fewer big rocks, the rock size distribution is much more skewed to smaller sizes here.

"Regarding what these rocks mean to the idea that there are lake deposits around here, it's way too early to tell because we don't have the slightest idea yet what these rocks are made of. ... It bodes well for our ability to learn more about them, in part because they do look like they've been so cleaned off nicely (by wind). But, too early to tell."

According to scientists, this image highlights streaks or tails of loose debris in the martian soil, which reveal the direction of prevailing winds. The picture was taken by the rover's panoramic camera. Credit: NASA/JPL/Cornell University

Spirit's landing site was officially renamed today in honor of the shuttle Columbia's fallen crew. A six-inch-wide plaque mounted on the pancam mast provides a tribute to the astronauts and their mission. Spirit's landing site, NASA said in a statement, will henceforth be known as the Columbia Memorial Station. The Mars Pathfinder landing site was named the Sagan Memorial Station in memory of astronomer Carl Sagan.

"As team members gazed at Mars through Spirit's eyes, the Columbia memorial appeared in images returned to Earth, a fitting tribute to their own spirit and dedication," NASA Administrator Sean O'Keefe said in a statement.

Earlier today, President Bush called the Spirit flight control team at the Jet Propulsion Laboratory to offer the nation's congratulations. JPL Director Charles Elachi said the conversation lasted about 10 minutes.

"He complimented the team, say ing that they represented the best of our nation," Elachi said. "He called our effort a confirmation of the American spirit of exploration. He thanked them for daring to be great and called the landing of Spirit a proud moment for all Americans. And finally, he talked about this mission as being an inspirational moment, especially for the next generation of explorers, the young children in school today."

Elachi invited the president to visit the Jet Propulsion Laboratory. Spirit mission manager Jennifer Trosper went one better, inviting Bush to try his hand at driving the rover. "But very carefully," Trosper said.

"And then we had a little chat about quantum physics and string theory," Elachi joked. "Needless to say, the NASA administrator, Sean O'Keefe, and I could not have agreed more with the kinds of words the president said about the team. We said it was another proud day for NASA, for JPL, for Cal Tech ... we were all very excited and very proud to hear from our president and how proud he feels about this team."

The activation and checkout of the Spirit rover continues. Trosper said it now looks like the rover will not drive off its lander onto the martian surface until next Tuesday or Wednesday. Overnight, engineers plan to begin the three-day process of jacking Spirit up, extending its wheels and locking its undercarriage in place for roving.

Before all of that takes place, however, engineers want to complete the job of fully retracting the airbags crumpled up to either side of Spirit's front end. Trosper said the preferred exit route for the rover is straight off the lander, to the south, and the airbags could pose problems by hiding underlying rocks.

Engineers had planned to begin additional airbag retraction work earlier today, but the operation was pushed back one day and now will be carried out overnight. Jessica Collisson said engineers were able to confirm the airbags in question are attached to the lander's base plate. A retraction mechanism will be commanded to make three full revolutions late tonight or early Wednesday to pull the bunched-up material inward, under the petal. Photographs then will be taken to determine what effect the mechanism had.

Only two other issues are even under discussion. Spirit's electronic systems are running slightly hotter than originally expected, prompting mission managers to delete one of three daily UHF communications sessions. That will reduce the heat generated by the radio system's electronics. Once the rover moves off onto the cooler martian surface, Trosper said, the temperature issue should be resolved.

The other issue involves Spirit's high-gain antenna. During deployment, a motor that elevates the antenna so it can lock onto Earth showed very brief current spikes indicating slightly rougher-than-expected operation. Tests are planned to further characterize the issue to make sure routine operations later don't cause damage. Until the tests are complete, mission planners are using Spirit's low-gain antenna and UHF communications sessions with the Mars Global Surveyor and Mars Odyssey orbiters.

Otherwise, Spirit's checkout is going swimmingly.

"The object of our affection is doing quite well on the surface of Mars," said Firouz Naderi, director of Mars exploration at JPL. "Evidently, we're also getting the (public) fully engaged. I believe we have passed one billion hits on the internet on the rover.

"In the next few days, the parents of this rover will help it to its feet and help it take the first baby steps, first on the lander and then eventually on the surface. But as far as communications are concerned, if you take images as the means of communication, this baby has skipped all the baby talk and has gone right into full sentences."

Squyres tried to read a few of those sentences by pointing out features in the first pancam postcard that were particularly interesting.

"The surfaces of the rocks are remarkably smooth and the shapes are quite varied, some of them very rounded, some of them quite angular," he said. "The way in which this kind of appearance tends to come about geologically, and I'm getting into hypotheses right now - that's a fancy way of saying I'm speculating - is if you have a very strong, very fine-grain rock that gets broken up by some process, we don't know what, and then is exposed for a long period of time to, effectively, sand blasting.

"If you have a lot of wind in an area like this and you have a lot of fine-grain debris that is bouncing off the sides of the rocks, it can sort of polish them. And rocks that originally form and break in angular shapes will retain their angularity, but will have their facets smoothed off by the process. Rocks that start off round will stay round, but they will have their surfaces smoothed by this process. What we're seeing is typical of rocks that go through that."

"This tells us nothing yet about the composition of these rocks," Squyres said. "That's yet to come. We're taking two mini-TES (thermal emission spectrometer) octants, that is 90 degrees worth of mini-TES panorama, today. We took 90 degrees worth of mini TES panorama yesterday, we're hoping to have that down on the ground very soon. So once we've got that stuff, we'll start to get a taste of what these things are really made of."

For Bell, the first picture was worth far more than a thousand words.

"My reaction (to the first pancam image) has been one of shock and awe," he said. Previous tests of the camera system on the ground were a bit like "having an animal in a cage."

"There are walls and there's stuff close by out of focus," he said. "And now this beast is out! It's out there taking these incredible pictures in the native habitat it's supposed to be working in. We designed it to do this so we shouldn't be surprised, but boy, it's spectacular looking at the details!"

Before the Mars Exploration Rover mission is over, Squyres said, Bell will be known as "the Ansel Adams of the space age."

"This is just the tip of the iceberg in terms of what you're about to see in the way of images," Squyres said. "This is something like one eighth of a single pancam panorama and this isn't stereo. We're going to have stereo pancam come down fairly soon, too, and that's going to be just stunning. So this is just a tiny taste of what's to come."

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