Tag: Valles Marineris

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Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on November 2, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows just one small section of a ridge that descends deep into the giant canyon Valles Marineris, the largest known canyon in the solar system.

On the overview map above, the white dot inside the rectangle marks the location, in the westernmost section of the part of Valles Marineris dubbed Ius Chasma.

For scale, the nose of this ridge descends about 7,300 feet from the top to the bottom, about half the total descent from the small isolated plateau shown in the inset. That plateau, located in the mountainous region between Ius Chasma and Tithonium Chasma, rises to approximately the same elevation as the canyon’s rims to the north and south.

What this picture shows us is that Valles Marineris on its western end is both more shallow and broken up, forming several canyons and plateaus. As the catastrophic floods that are theorized to have carved this canyon pushed their way east, they carved a deeper gorge, so that about 1,500 miles to the east the canyon walls are considerable higher, from 20,000 to 30,000 feet in some places.

As always, the tourist in me can’t help look at this terrain and envision inns and hiking trails. Imagine homesteading that plateau where you build a hotel and trails. Since I expect much transportation on Mars will be by air, your guests would fly in, land at a heliport, and spend their visit hiking down into the canyons that surround them.

Damn! The future is going to so grand!

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Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on October 15, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The white dot on the overview map above shows the location, on the northern interior wall of the vast Valles Marineris canyon on Mars.

As my readers know, I tend to look at the spectacular Martian photos coming back from the orbiters and rovers as much from a tourist perspective as that of a scientist. Thus, for this picture, my first thought was to consider the possibility of a trail weaving its way down the nose of that ridgeline and into the canyon. In the Grand Canyon such ridgelines often provide a route down where walking is possible the entire way, with no need for climbing or ropes.

To illustrate my thought, I have indicated the potential trail with the white line. All told this trail covers about 7.2 miles, and drops 12,500 feet. Such a drop is very steep for trails on Earth, with an average grade of 14 degrees and about three times the grade considered reasonable. On Mars, however, with its one-third gravity, I think a grade this steep would be reasonable, though certainly daunting mentally. You would not only be descending on a very steep slope, you would be doing so on the peak of this ridge, with drops of one to two thousand feet on either side.

Amazingly, the inset on the overview map shows that this trail gets you less than halfway to the bottom. All told, the drop from canyon rim to floor at this location is about 31,000 feet over 20 miles, a drop that is greater than climbing down from the top of Mount Everest. If I was to install a trail here I’d also build an inn or two along the way as rest stops for hikers.

What the trail would do is get you to the bottom of this particular ridgeline. From here the trail would have to drop off into the western hollow and from then on descend on top of its alluvial fill. The slope would be as steep, but it would be possible to alleviate that by putting in switchbacks. This would lower the grade, but increase the distance traveled significantly.

Geologically, this image shows to my eye one particular feature that is quite significant, at the rim. I will discuss this tomorrow, in my next cool image.

Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on July 26, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The red dot in the overview map above marks the location, within the western reaches of the vast Martian canyon dubbed Valles Marineris.

The picture looks at the flow of dust and sand going down the canyon’s southern rim, with particular focus on the central canyon in the picture’s center. The photo was taken as part of a long-term project, begun in 2020 to monitor this river of sand to see if any changes occur over time. Clearly the sand is flowing downhill, almost like a river, with the dunes almost resembling waves. The geological issue is to determine how fast. Based on the resolution available to me, it is impossible to tell it there have been any changes in the past four years, but the full MRO dataset might reveal more information.

To get an idea of scale, the elevation loss from the top to the bottom in this picture is about 6,000 feet. While this seems like a substantial amount, it pales when placed in the context of Valles Marineris. For example, the elevation loss for the canyon’s northern wall is about 25,400 feet, making that wall exceed in height most of the mountains in the Himalayas. And that wall extends for more than 1,500 miles.

Valles Marineris’ southern wall is more complex. It rises about 18,000 feet from the floor of the canyon to the top of the peak on which this slope sits, but then drops 6,700 feet into a parallel side canyon. From there the rise to the southern rim is about 11,000 feet. All told the southern rim sits about 23,000 feet above the canyon floor, once again a drop that would exceed most mountains on Earth.

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Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on May 24, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). Labeled merely a “terrain sample” by the camera team, it was likely taken not as part of any particular research project, but to fill a gap in the picture-taking schedule in order to maintain the camera’s proper temperature.

When the camera team needs to do this, they try to pick interesting targets within the required timeframe. Sometimes they succeed, sometimes not. In today’s example, they succeeded quite well. As shown by the overview map above, this picture captures (as indicated by the rectangle) the top of the southern rim of Valles Marineris, the biggest canyon on Mars and quite possibly the biggest in the entire solar system.

For scale, the drop from the rim to the low point in this picture is about 9,000 feet. That’s a 1,000 feet more than the drop from the north rim of the Grand Canyon to the canyon bottom at the Colorado River. In Valles Marineris however our descent has barely begun. To get to the bottom of the southern canyon here you still need to drop 15,000 more feet, for a total descent of 24,000 feet, an elevation change similar to most of the mountains in the Himalayas.

Nor are you yet at the bottom. If you climb over the ridge of 18,000-foot-high mountains that bisect Valles Marineris at this point, you can drop down even further, to a depth 31,000 feet below the southern rim.

Mount Everest is just over 29,000 feet high, which means if placed inside Valles Marineris is peak would still sit 2,000 feet below the rim.

The photo itself highlights part of the erosion process that formed Valles Marineris. This is the dry tropics, so no water was involved in shaping this terrain for many eons. Instead, what appear to be flows within the hollows is alluvial fill, material that over time breaks off and rolls downhill, filling the slopes below. Erosion will grind this material into smaller particles, so given enough time it flows almost like sand.

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Today’s cool image returns us to the truly spectacular terrain found on the floor of West Candor Chasma, one of the giant side canyons that form Valles Marineris, the biggest canyon in the solar system, many times larger than the Grand Canyon on Earth.

The picture to the right, cropped, reduced, and sharpened to post here, was taken on January 5, 2024 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). On the overview map above its location is indicated by the red dot in the inset. The two green dots mark previous cool images from August 2022 and February 2024.

All three images show the same wild alternating dark and light terracing, suggesting many sedimentary layers like those seen in our Grand Canyon, but enhanced by the different erosion processes of the thin Martian atmosphere and its one-third Earth gravity.

The second image to the right zooms in on the area indicated by the rectangle. What makes this area doubly interesting are the cracks that appear to cut through the terraces. In the north-south crack it also appears that the terraces are now offset on each side of the crack.

Apparently, some event, likely an earthquake that occurred after the terraces formed, caused the ground to rip apart, with the earth shifting sideways on either side. Though the seismometer on the InSight lander detected no major quakes in this region, this image suggests they have occurred here, sometime in the past.

To give you a sense of scale, the canyon’s nearby rim to the west is about 14,000 higher, making that canyon wall two to three times taller than the walls of the Grand Canyon.

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Cool image time! The picture to the right, cropped, reduced, and sharpened to post here, was taken on September 26, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a field of scattered elongated dunes on a flat older surface with craters and what appear to be smaller ripple dunes (in the lower left). The large elongated dunes tend to be oriented in an east-west manner, while the older tiny ripple dunes appear to have a north-south orientation.

Very clearly the larger dunes appear to be traveling across that flat older surface, though whether there is any documented movement is unknown. Generally (though there are exceptions) scientists have found most of the dunes on Mars to be either inactive, or if they are moving because of the wind that movement is very tiny per year. In this case there is one dark spot on the dunes, near the center of the picture, where it appears a collapse might have occurred, suggesting recent change.

On the center right of the picture is the end point of a long ridgeline extending 10 to 12 miles to the east and rising about 7,300 feet, as shown in the overview map above. The small rectangle in the inset shows the area covered by the photograph.

At the base of that ridgeline can be seen a series of terraces descending to the west, suggesting that this hill might be volcanic in nature, with each terrace indicating a separate lava flow. The location is in the dry equatorial regions, so near-surface ice is likely not an explanation.

In the inset the mountain wall to the north is the large mountain chain that bisects this part of Valles Marineris. It overwhelms this small 7,300-foot-high ridge, rising more than 22,000 feet from these dunes with its high point still one or two thousand feet below the rim of Valles Marineris itself.

Once again, the grand scenery of Mars amazes. Imaging hiking a trail along that ridgeline, with the mountains rising far above you to the north and south.

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Time for another cool image showing the dramatically steep terrain of Valles Marineris on Mars, the largest known canyon in the solar system. The picture to the right, cropped, reduced, and enhanced to post here, was taken on October 31, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

The scientists rightly label this picture “Steep Slopes in West Melas Chasma”. The red dot marks the high point on this ridgeline. The green dot at the upper left marks the lowest point in the picture, about 4,800 feet below the peak. The blue dot on the right edge marks the low point on the ridge’s eastern flank, about 4,600 feet below the peak. The cliff to the east of the peak drops quickly about 1,300 feet in less than a mile.

On the overview map above, the white dot marks the location. The inset is an oblique view, created from a global mosaic of MRO’s context camera images, with the white rectangle indicating approximately the area covered by the picture above.

The immense scale of Valles Marineris must once again be noted. The elevations in this picture are comparable to the descent you make hiking down from the South Rim of the Grand Canyon. They pale however when compared to Valles Marineris. In the inset I have indicated the rim and floor of Valles Marineris in this part of the canyon. The elevation distance between the two is 18,000 feet.

In other words, the canyon to the east of this ridge is quite comparable in size to the Earth’s Grand Canyon, and it is hardly noticeable within the larger canyon of Valles Marineris.

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Time for another cool image of the grand canyon of Mars, Valles Marineris. The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on May 24, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows a small section of the floor of this gigantic canyon, where orbital data has detected light-toned materials. From the caption:

Many of the Valles Marineris canyons, called chasmata, have kilometer-high, light-toned layered mounds made up of sulfate materials. Ius Chasma, near the western end of Valles Marineris, is an exception.

The light-toned deposits here are thinner and occur along both the floor and walls, as we see in this HiRISE image. Additionally, the sulfates are mixed with other minerals like clays and hydrated silica. Scientists are trying to use the combination of mineralogy, morphology, and stratigraphy to understand how the deposits formed in Ius Chasma and why they differ from those found elsewhere in Valles Marineris.

The picture however gives no sense of the monumental terrain that surrounds it.
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Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on July 14, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), showing the very bottom section of the long and endlessly deep south slopes of Valles Marineris, the largest known canyon in the solar system.

The many layers here are likely evidence of repeated volcanic flood lava events, over several billion years, after which the canyon formed.

On the overview map above the black dot in the southeast section of the area of the canyon dubbed Melas marks this location. The picture’s northeast corner is essentially the floor of Valles Marineris. From this point the elevation gain to the southwest corner of the picture 3.5 miles away is about 3,300 feet.

The rim itself however is far far higher, about fifty miles farther to the southwest and climbing about 22,000 feet more. Along those fifty miles you’d have to also climb over two intervening mountain ranges, one about 4,000 feet high and the second about 6,000 feet high.

Valles Marineris is big, so big it is hard to imagine a canyon this size. It makes many moutain ranges on Earth seem small.

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While the giant canyon Valles Marineris on Mars is known best as the biggest known canyon in the solar system — large enough to cover the continental United States several times over — that size tends to diminish the mountainous nature of its interior. Today’s cool image attempts once again (see for example these earlier posts here, here, here, here, and here) to illustrate that stupendous and mountainous nature.

The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on May 15, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). The goal of the picture was to get a better view of the numerous layers of this terraced cliff wall. What I see, however from my tourist’s perspective, is a steep wall that descends almost 4,500 feet from the high to the low point in just over three miles. This is as steep if not steeper than the walls of the Grand Canyon.
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Cool image time! The picture to the right, rotated, cropped, and reduced to post here, was taken on June 27, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO).

I have cropped it to focus on this one hill, about 900 feet high (though the elevation data from MRO is somewhat uncertain at this resolution), because of that major landslide on its northern slopes. At some point in the past a major piece of the exposed bedrock at the top broke off and slide about halfway down the mountain, almost as a unit, settling on the alluvial fill that comprises the bottom half of the hill’s flanks.

The bedrock surrounding the peak is also of interest because of its gullies, all of which were created by downward flowing material. Was it ice? Water? Sand? Or maybe a combination of two or three? If water or ice was involved it was a very long time ago, as this location is in the dry equatorial regions of Mars. There is little known near-surface ice here.
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Cool image time! The picture to the right was created from a global mosaic of all the context camera images taken by Mars Reconnaissance Orbiter (MRO) since it entered Mars orbit in 2006. It shows an unnamed 17-mile-wide-depression located only about seven miles south of the southern rim of Valles Marineris.

I highlight this particular depression because, despite seventeen years in orbit, MRO’s high resolution camera has at this time still not taken any pictures inside or around it. This is a place on Mars that remains unstudied in detail, in any way, even though its depth is comparable to the Grand Canyon and its features strongly suggest its is a collapse feature, created when the roof over an underground void gave way. If so, it suggests an origin for Valles Marineris that conflicts with present theories.
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This week I have returned several times to the giant Valles Marineris canyon on Mars in an attempt to capture its incomprehensible and glorious scale. Without question this canyon is going to become one of the prime tourist spots when humans begin living and working throughout the solar system. Fortunately, its vast size will mean that it will take many many centuries before it even becomes close to crowded there.

Today I try a different approach, using the global mosaic created by scientists at Caltech from the context camera images taken by Mar Reconnaissance Orbiter (MRO). That mosaic processes the images to allow one to see the surface from an oblique angle. The picture to the right covers one small part of the eastern end of Valles Marineris (the white rectangle in the inset), but though small the scale once again is gigantic.

The three white dots are our reference points, one on the north rim, one on the south, and one in the middle on the peak of that central mountain chain. Beginning from the south, the distance from the rim to the middle mountain peak is 43 miles, with the elevation dropping almost 13,000 feet to the floor of the south canyon, than rising almost 10,000 feet to the middle peak. The northern canyon is smaller. From the peak to the north rim is 27 miles, dropping about 9,300 feet and then rising about 8,500 feet to the north rim.

From rim to rim the distance is about 70 miles. Since the middle mountain chain about 18 miles wide, it fills only about 25% of the entire canyon.

In every case, the Grand Canyon would be merely be a small side canyon here. The depths are twice as deep, and the distances are many times larger. In width alone at this point Valles Marineris is seven times wider than the widest part of the Grand Canyon, and this is by far not Valles Marineris’s widest point.
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The opportunity to see more mind-blowing examples of spectacular views on Mars compels me to post another great view of a mesatop within Valles Marineris, the biggest known canyon in the solar system. The picture to the right, rotated, cropped, and reduced to post here, was taken on May 14, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows an 800-foot-high mesa with two points at its end, the cliff wall below highlighted by numerous layers, many alternating between light and dark material.

The erosion features on the top of the mesa suggests some flow down its middle and into the gap between its two end points. This is the dry equatorial region of Mars, so no near surface water is presently found. In the far past maybe ice, or theorized catastrophic floods of water, caused this erosion.
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Cool image time! The picture to the right, rotated, cropped, reduced, and sharpened to post here, was taken on February 19, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO). It shows the many many many layers that are found in the cliffs of Valles Marineris, the largest known canyon in the solar system and far far larger that Earth’s Grand Canyon.

The elevation difference between the red dots is just under 4,000 feet. Yet that high point is still more than 7,000 feet below the rim of the canyon, more than thirty miles to the south. And the lower dot is still about 18,000 feet above the low point in this side canyon of Valles Marineris, about thirty miles away to the northeast.

In other words, in sixty miles from rim to floor the canyon at this location drops about 25,000 feet, only 4,000 feet less than the height of Mount Everest. Compare that with the Grand Canyon’s slopes, which drops in eleven miles about 5,000 feet, beginning at the main south rim lookout at the start of Bright Angel trail.
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Cool image time! The picture to the right, rotated, cropped, and sharpened to post here, was taken on December 28, 2023 by the high resolution camera on Mars Reconnaissance Orbiter (MRO), and shows one tiny section of the interior slope of the giant Martian canyon Valles Marineris.

The while layers are not made of frost or ice, because they are light tan, as per the color image. Thus, the alternating layers of dark and light indicate different layering events. The dark layers are probably major lava flood events with a lot of dark ash intermixed, while the tan layers were flood lava events with little dark ash.

The dark lines that cut across these layers are ripple dunes formed from dust that has accumulated inside Valles Marineris.
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