Archive for the ‘HiRISE’ category

Weird Outcrops in Schiaparelli Crater

February 6, 2009

Today while we were discussing the section of the MOC paper that I posted about yesterday, we decided to look more closely at one of the figures. In the paper, the authors suggest that the light-colored rocks are on top of the dunes, implying that the dunes are fossilized, were buried and are now being uncovered. We found a HiRISE image of the area and found out that the truth is even stranger. It doesn’t look to me like the light-toned rock is on top of the sand ripples, and in some places, the ridges in the sand gradually merge and become ridges in the rock! And the bedrock itself is really strange looking itself: it reminds me of feathers and scales, though in reality its surface is covered with shallow “scoops” or a “scalloped” texture. My best guess is that this is a fine-grained, soft rock that has been eroded into this texture by the wind. How the light-toned rock and the sand ripples are related, I can’t tell for sure…

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New Google Mars

February 2, 2009

Google Earth’s latest edition was just released and guess what? It has a Mars setting! There was a way to overlay Mars data on the Earth globe in previous versions, but now that’s no longer necessary: just click a button and you’re on Mars. You can choose from a variety of global maps including topography, Viking images, Day and nighttime infrared, and visible color. It also has footprints for high resolution cameras like HiRISE, CTX, MOC, CRISM, and HRSC, with links to the full-resolution images. And most exciting, it has 3D topography! Now you can fly around in Valles Marineris or check out the view from Olympus mons.

The view from the edge of the Olympus Mons caldera in Google Mars.

The view from the edge of the Olympus Mons caldera in Google Mars.

Olympus Mons dominates the horizon in this Google Mars view.

Olympus Mons dominates the horizon in this Google Mars view.

Another way-cool feature is the ability to zoom into panoramas taken by rovers and landers, as shown here for Opportunity.

The Opportunity rover's traverse. Each camera icon is a panorama that you can zoom into.

The Opportunity rover's traverse. Each camera icon is a panorama that you can zoom into.

Part of the Rub al-Khali panorama taken by the opportunity rover.

Part of the Rub al-Khali panorama taken by the opportunity rover.

And finally, you can load selected Context Camera images right onto the globe, to take a high-res look at areas of interest, such as the Olympia Fossae troughs shown here. I don’t know what’ you’re waiting for: go download the program and try this out for yourself!

CTX image of the Olympia Fossae troughs.

CTX image of the Olympia Fossae troughs.

Mars in 3D

December 11, 2008

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Apparently the folks on the HiRISE team decided that spectacular images weren’t enough. They have now released hundreds of 3D HiRISE images on their website, including the one above of layered rocks and sand dunes in Arabia Terra. (you may recognize this scene from my Mars Art post a few weeks ago) Grab your 3D glasses and enjoy!

Mars Art: Rhythmic Layers

December 8, 2008

This week’s Mars Art image also happens to be the subject of an interesting new finding. A new paper in Science details the discovery of a set of layered deposits in Arabia Terra that appear to match the Martian Climate cycle. Mars’ tilt wobbles around and causes the climate to change with it. It follows the general pattern of ten smaller wobbles in between larger wobbles. The layers shown in this week’s picture follow the same pattern, with layers occuring in bunches of ten. So, not only are these layers cool-looking, they also contain some really interesting science. Check out the press release for more info, and the multimedia page for some cool videos that simulate flying over the layers.

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Mars Art: Dunes in Abalos Undae

November 24, 2008

This week’s Mars Art is a HiRISE view of Dunes in Abalos Undae. Pictures of sand dunes taken by HiRISE never get old for me. There is something about the undulating, regular shapes of dunes that is fascinating and beautiful and peaceful. There is a great quote about dunes in the book “Physics of Blown Sand and Desert Dunes” by R.A. Bagnold that goes on quite poetically about them, but unfortunately I don’t have it close at hand. Consider this an IOU. which Briony has posted below! Meanwhile, enjoy the picture, and read more about it here.

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Update from Briony: Here’s an awesome Bagnold quote, hopefully the one that Ryan was referring to:

In places vast accumulations of sand weighing millions of tons move inexorably, in regular formation, over the surface of the country, growing, retaining their shape, even breeding, in a manner which, by its grotesque imitation of life, is vaguely disturbing to an imaginative mind.
~ Bagnold (1941)

Mars Art: Linear Dunes near the North Pole

October 28, 2008

I am starting a new thing. Every week, I will browse through data from current and past Mars missions and find an “artistic” image to post here. I’ll talk briefly about what the image says scientifically, but mostly this is about eye-candy and the crossover between science and art, which I have talked about before. Without further ado, here’s your first piece of “Mars Art”:

This image is a HiRISE view of linear dunes near the Martian north pole. The shape of the dunes themselves indicates that winds in this area tend to vary, first blowing along the dunes from one side, then the other, but always in a generally west-southwest direction. Between the dunes, the bare ground shows polygonal cracks similar to the ones that Phoenix landed on. These cracks are a good indicator of permafrost in the soil. Click for a higher resolution jpeg, or go to the HiRISE site to learn more about the image or to look at the full-resolution version.

Fresh Craters

October 21, 2008

Today marks my twenty-fourth revolution around the sun! To commemorate this momentous occasion, I am going to be a lazy blogger and just let you drool over some HiRISE images instead. The image above is a small crater in the polar layered deposits. It’s filled with ice because the crater walls keep the floor shaded, so frost can collect there. You can read more about this crater at the HiRISE site.


The second image is of dunes and what appears to be a very fresh crater near Uzer crater. The small crater in this image is surrounded by dark ejecta which hasn’t been eroded away yet. If you have a sharp eye, you can also see that there are strange raised cracks in the plains west of the small crater. My guess is that those are ridges formed when water flowed through cracked bedrock and altered the rock near the cracks, making it erosion-resistant. You can read more about this image at the HiRISE site, though they focus on the bigger crater that is outside the field of view of this close-up.

Planets as Art

October 6, 2008

I’m often struck by how beautiful landscapes are when seen from above, whether they are on Mars, Earth, or anywhere else. With the high-resolution images from HiRISE this is especially true; with such a close view, the scale and context can be lost, and the images become more akin to abstract textures. Here’s a great example: It’s a dune field inside a crater on mars, but it looks like rumpled satin or waves on dark water.

The same is true for views of the Earth: when we can look down from above we can see things differently and even barren landscapes and polluted cities can be beautiful.¬† Today’s post over at The Big Picture has a fantastic series of images of the earth from above. I especially liked this one of Iceland:

I’m not the only one who thinks that the beautiful images taken of planets qualify as art. In fact, Cornell is hosting the 40th annual Division for Planetary Sciences meeting next weekend, and along with the conference the art museum on campus is displaying a selection of spectacular images from the Cassini-Huygens mission to Saturn. The Cornell Symphony Orchestra will also be playing Holst’s famous symphony “The Planets“, with a photographic accompaniment assembled by myself and many others. (we’re hoping to post the videos online at some point) They’ll also be playing a never-before-performed piece of music inspired by the same amazing images of Saturn that will be on display at the art museum.

It is easy to think about science and art as existing totally isolated from one another, but both are among humanity’s greatest accomplishments. It only seems fitting that they sometimes overlap.

Plumbing on Mars: HiRISE Reveals Groundwater Cracks

September 26, 2008

This image from the HiRISE camera on the Mars Reconaissance Orbiter, shows cracks in the rocks on Mars that once formed the underground plumbing through which groundwater traveled.

Groundwater flow on Mars has been speculated for a long time, but it takes powerful cameras like HiRISE to actually find the evidence. These cracks resisted erosion because they were filled with minerals deposited by groundwater, so now we can see them as positive relief.

From the press release:

“This study provides a picture of not just surface water erosion, but true groundwater effects widely distributed over the planet,” said Suzanne Smrekar, deputy project scientist for the Mars Reconnaissance Orbiter at NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “Groundwater movement has important implications for how the temperature and chemistry of the crust have changed over time, which in turn affects the potential for habitats for past life.”

Too bad we didn’t find these a year ago so they could be considered as an MSL landing site…

Potential MSL Site: Mawrth Vallis

September 17, 2008

The Mawrth Vallis landing site is actually a set of four possible landing ellipses in an area with huge clay mineral signatures that is cut by a meandering outflow channel. There was some grumbling in the past about the fact that Mawrth advocates proposed four ellipses when everyone else followed the rules and only submitted one, but in the end I think it hurt them. They ran way over time today and had to speed through several very good presentations.

Part of the reason they went over time is because their first presentation spent a long time trying to convince people that the mission must go to a location from early in Mars history. We already knew that! They also had a lot of overlap between the individual presentations. But anyway, on with the science.

Mawrth is a bonanza of clay minerals. We saw modeling evidence which indicates that in some places >60% of the minerals in the rocks have water in them. I don’t know how much I trust the models, and I am suspicious of such large numbers, but at any rate, if there are thick beds of clays anywhere on Mars, Mawrth is a great candidate for that. The great thing about Mawrth is that not only is there a very strong phyllosilicate detection, but there are both Aluminum and Iron/Magnesium bearing clays, and they have a definite stratigraphic relationship. Throughout the area, and even in locations hundreds of kilometers away, the same layers are seen: a bottom layer of iron/magnesium clays, a top layer of aluminum clays and hydrated silicates, and a capping layer of something else. In between the two clay layers there may be another layer that represents a chemical reaction between them.

There is also a lot of interesting morphology in the area, including polygons that seem to correlate with clays, fractures in the bedrock that have light or dark “haloes” around them that may indicate fluid flow, deformed layers of sediment, and filled craters. Also, some of the layers appear to follow the topography so that maybe they were draped over it. This would be possible if they were some sort of ash fall from a huge eruption, or some other sedimentary unit that was draped over and then altered in place.

As i mentioned briefly above, the same layering sequence is seen in areas many hundreds of kilometers away from Mawrth Vallis, meaning that if we figured out Mawrth, we could figure out a big area of Mars. One of the confusing things about Mawrht is that there is no clear basin that would collect sediment, so the question arises: how do we know that these are huge stacks of ash or dust or sand or something blown by the wind? This was discussed at great length, but the bottom¬† line that I took away was that, yes, it could all be air-blown. John Grotzinger, the project scientist, pointed out that on Earth, we learn a lot from stuff that has been transported and that to him it’s still an interesting site whether the clays were transported or formed in place.

Some people expressed the thought that, after being bombarded by a series of presentations about the site, they couldn’t see how a story would come out of it. The response to this was that, yes it is complicated, but it is not a complete mess with no coherent relationship. There are a lot of observables at the site with MSL, and I found this complaint kind of odd for this site. The group presenting showed us lots of hypotheses even if they didn’t call them that, and I don’t think it would be incomprehensible from the ground with the rover.

One of the final points raised was that, if the layers appear to drape current topography, how do we know they aren’t much younger than they seem. The answer given to this was extremely unsatisfying to me. Basically they said that one current theory (which happens to be the favorite one of the proposers of this site, since they came up with it) says that phyllosilicates formed early in Mars history, and therefor this site with phyllosilicates must be from that period. That wasn’t how they said it, but that’s what it amounted to, and that’s dangerous thinking.

Mawrth is definitely a fascinating site that could tell us a lot about Mars, and it has the best evidence for clay minerals seen on the planet. But life can be well preserved without clays and clays don’t always preserve life. A lot of people at this workshop are equating clays with biomarker preservation but it is not that simple. I think the presenters shot themselves in their collective feet by not being organized, not following the same pattern that the other presentations did and running way over time. I like Mawrth, but I came away feeling like there is a lot that we don’t know regarding its habitability and potential to preserve organics, so I don’t know if it will be carried.