Starship Asterisk*

Ann wrote:A truly fascinating thing about this shot is that there is now enough man-made technology on and in orbit around Mars that it is in fact possible to use one probe to photograph another.

neufer wrote:

Anthony Barreiro wrote:
Can anyone explain the small perpendicular rifts on the surface to the right of the lander?

http://en.wikipedia.org/wiki/Mudcrack wrote:

[b][size=175][color=#DF6000]Fresh mud cracks[/color][/size][/b]

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[img3="Colorized relief map of Gale Crater. The Aeolis Palu landing area
for Curiosity on the northwestern crater floor,
and 4 km below "sea level," is circled. (HRSC data)"]http://upload.wikimedia.org/wikipedia/c ... Crater.jpg[/img3]

<<Mudcracks (also known as desiccation cracks) are sedimentary structures formed as muddy sediment dries and contracts. Naturally forming mudcracks start as wet, muddy sediment desiccates, causing contraction via a decrease in tensile strength. Individual cracks join up forming a polygonal, interconnected network. These cracks may later be filled with sediment and form casts on the base of the overlying bed. Syneresis cracks are broadly similar features that form from subaqueous shrinkage of muddy sediment caused by differences in salinity or chemical conditions, rather than subaerial exposure and desiccation.

Mudcracks are generally polygonal in plan view and v-shaped in cross section. The "v" opens towards the top of the bed and the crack tapers downward. Allen (1982) proposed a classification scheme for mud cracks based on their completeness, orientation, shape, and type of infill.

Complete mudcracks form an interconnected network. The connection of cracks often occurs when individual cracks join together forming a larger continuous crack. Incomplete mudcracks are not connected to each other but still form in the same region or location as the other cracks.

Orthogonal intersections can have a preferred orientation or may be random. In oriented orthogonal cracks, the cracks are usually complete and bond to one another forming irregular polygonal shapes and often rows of irregular polygons. In random orthogonal cracks, the cracks are incomplete and unoriented therefore they do not connect or make any general shapes. Although they do not make general shapes they are not perfectly geometric. Non-orthogonal mudcracks have a geometric pattern. In uncompleted non-orthogonal cracks they form as a single three point star shape that is composed of three cracks. They could also form with more than three cracks but three cracks in commonly considered the minimum. In completed non-orthogonal cracks, they form a very geometric pattern. The pattern resembles small polygonal shaped tiles in a repetitive pattern.

Naturally occurring mud cracks form in sediment that was once saturated with water. Abandoned river channels, floodplain muds, and dried ponds are localities that form mudcracks. Mud cracks can also be indicative of a predominately sunny or shady environment of formation. Rapid drying, which occurs in sunny environments, results in widely spaced, irregular mud cracks, while closer spaced more regular mud cracks indicates a shady formation environment. Polygonal crack networks similar to mudcracks can form in man-made materials such as ceramic glazes, paint film, and poorly made concrete. Similar features also occur in frozen ground, lava flows (as columnar basalt), and igneous dykes and sills.>>

owlice wrote:Anthony,

Here ya go:

http://apod.nasa.gov/apod/ap120222.html

http://www.planetary.org/blogs/emily-lakdawalla/2012/08091249-curiosity-sol-3-mastcam-pan.html wrote:
Curiosity sol 3: First Mastcam color thumbnails down, everything "flawless," "nominal"
Posted By Emily Lakdawalla, Planetary Society, 2012/08/09

[b][color=#0000FF]An attempt to colorize part of a Navcam image of the eastern flank of Aeolis Mons with the Mastcam thumbnail color panorama released on sol 3. NASA / JPL / MSSS / Emily Lakdawalla[/color][/b]

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Click to play embedded YouTube video.

Click to play embedded YouTube video.

<<Today's press briefing covered Curiosity's sol 3, the third full day of operations on Mars. (Landing was sol 0; different missions have used different conventions for numbering landing day.) Everything on sol 2 and 3 has gone essentially flawlessly, mission manager Mike Watkins reported. And not just on Mars; on Earth, with the function of the team, too. Which, considering the size of this team and the short planning schedule they have each day, is quite an accomplishment. Of course, it helps that most of their sequences for the first few weeks are essentially pre-planned.

The big thing that everyone was looking forward to today was a report on how the Mastcam panorama did. To briefly review, Mastcam is the main color science camera on top of the mast; there are two cameras, one a medium-angle view (Mastcam-34) and one a zoom (Mastcam-100). Up on Mars, Mastcam successfully acquired the entire panorama, 130 images. It returned thumbnail versions of all of those images to Earth, 144-pixel previews of what will eventually be 1200-pixel images. Mike Malin presented a panorama made from those thumbnails, and it's very pretty, but only a preview of what's to come. I'm a lesser image processor than some of the geniuses over there, so I didn't even attempt the full panorama. But I thought I could give a try to a little piece of it: that geological promised land on the right-hand flank of Gale's central mountain. The result isn't perfect by a long shot, but I'm pretty pleased anyway.

During tonight and tomorrow's communications passes, sol 4, they should get a few of the full-resolution frames down from Mars. But only 10 or 20 will make it down before they begin the big flight software upgrade on sol 5. That effort will take at least 4 sols, and no science data will be returned during that time. So it'll be some time -- at least a week, more like two -- before the whole thing is available in full resolution. Even then, it won't include the top of the mountain. The panorama was planned and sequenced before the landing, so its pointing was pretty much random. Malin said that in the coming couple of weeks they have other preplanned image mosaics but that they will be able to adjust some parameters, shifting pointing slightly to better frame the pretty vistas in the distance, and the intriguing geology they contain.

I asked Malin during the press briefing if it was true -- as is my impression -- that this is a more colorful landing site than any previous one. He said he agreed with that, though he was cautious about interpreting that. Different colors don't necessarily mean different rocks. All over Mars we have red dust, black sand, tan rocks, and those are the colors we're seeing here, too. Different appearance may thus have as much to do with texture as with composition. But Dawn Sumner, also on the panel, pointed out that we know there is diverse geology here; that's why we came! And she's going to begin to try to use the MARDI color data on their HiRISE geologic maps to see how color correlates with geology.>>

neufer wrote:

http://en.wikipedia.org/wiki/Mudcrack wrote:
<<Naturally occurring mud cracks form in sediment that was once saturated with water. Abandoned river channels, floodplain muds, and dried ponds are localities that form mudcracks. Mud cracks can also be indicative of a predominately sunny or shady environment of formation. Rapid drying, which occurs in sunny environments, results in widely spaced, irregular mud cracks, while closer spaced more regular mud cracks indicates a shady formation environment.>>

http://astrobob.areavoices.com/?blog=78068 wrote:

[b][color=#0000FF]A part of the wall of Gale Crater north of the landing site shot with Curiosity’s high resolution camera. A network of valleys formed by water erosion long ago carved the rim. The main channel (labeled) looks like an arroyo or dirt road and is 11 miles away. Click to enlarge. Credit: NASA/JPL-Caltech/MSSS[/color][/b]

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<<One of the more interesting recent images from the rover shows a channel in the rocky rim of Gale Crater where water once flowed. According to NASA: “This is the first view scientists have had of a fluvial system – one relating to a river or stream — from the surface of Mars. Known and studied since the 1970s beginning with NASA’s Viking missions, such networks date from a period in Martian history when water flowed freely across the surface.”

We’ve seen these water-carved channels from orbit many times, but a ground level view makes it easier to imagine a Mars soaked with streams, lakes and maybe even an ocean.>>

Art Neuendorffer wrote:
"Well, [MSL's cruise stage] was coming in on exactly the same trajectory and with exactly the same escape velocity as Curiosity itself...but with no heat shield. What do you think happened to it?"

rkeefe57 wrote:
What do I think happened to it? If I knew that I wouldn't have asked. Seems a little reckless to have 900 pounds of flaming metal following your $2.5 billion dollar rover down to the ground. Thanks for the insight, though.

http://www.planetary.org/blogs/bill-nye/were-going-back-to-mars-in-2016.html wrote: Mars InSight Lander Mission
By Bill Nye, 2012/08/20

<<Today, NASA announced the newest Discovery-class mission, a Mars lander called InSight. It's not a rover; it's a drill that will go down 5 meters and help us figure out what happens in the core of our neighboring terrestrial planet. We should all keep in mind that along with the selection of this mission, NASA had to choose not to do two other fantastic missions, one to hop from asteroid to asteroid, and another that would have gone to Titan and float a boat on its liquid natural gas ocean. How cool would these have been? The price of these "Discovery Class" missions is so low compared to many, many other things that NASA and our government do. It's heartbreaking.>>