APOD: An Unusual Mountain on Asteroid Ceres (2015 Jun 30)

[neufer]

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that collision would be more interesting than a million year journey around Ceres.

• Not to the future curator of the Smithsonian Air & Space Museum collecting spacecraft from the Dawn of space exploration.

[ta152h0]

Pioneer 11 would be quite a story " and in this glass case is Pioneer 11 "

[neufer]

Pioneer 11 would be quite a story " and in this glass case is Pioneer 11 "

• Lotsa luck retrieving that!

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The Pioneer plaques are a pair of gold-anodized aluminium plaques which were placed on board the 1972 Pioneer 10 and 1973 Pioneer 11 spacecraft, featuring a pictorial message, in case either Pioneer 10 or 11 is intercepted by extraterrestrial life. The plaques show the nude figures of a human male and female along with several symbols that are designed to provide information about the origin of the spacecraft.

Originally Sagan intended for the humans holding hands, but soon realized that an extraterrestrial might perceive the figure as a single creature rather than two organisms. One can see that the woman's genitals are not really depicted; only the Mons pubis is shown. It has been claimed that Sagan, having little time to complete the plaque, suspected that NASA would have rejected a more intricate drawing and therefore made a compromise just to be safe. However, according to Mark Wolverton's more detailed account, the original design included a "short line indicating the woman's vulva". It was erased as condition for approval by John Naugle, former head of NASA's Office of Space Science and the agency's former chief scientist.

Sagan himself, however, later wrote: "The decision to omit a very short line in this diagram was made partly because conventional representation in Greek statuary omits it. But there was another reason: Our desire to see the message successfully launched on Pioneer 10. In retrospect, we may have judged NASA's scientific-political hierarchy as more puritanical than it is. In the many discussions that I held with such officials up to the Administrator of the National Aeronautics and Space Administration and the President's Science Adviser, not one Victorian demurrer was ever voiced; and a great deal of helpful encouragement was given… The idea of government censorship of the Pioneer 10 plaque is now so well documented and firmly entrenched that no statement from the designers of the plaque to the contrary can play any role in influencing the prevailing opinion. But we can at least try.">>

[geckzilla]

It doesn't make sense that the man gets to be intact but the woman has been altered. Well, at least she got nipples. It seems a lot of cultures are very insecure about the female body.

[neufer]

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It doesn't make sense that the man gets to be intact but the woman has been altered. Well, at least she got nipples. It seems a lot of cultures are very insecure about the female body.

There's a very real concern that most aliens are rapists
(although some, I assume, are good "Quantum Presbyterians").

[ta152h0]

" intact " is not the first think my wife thinks of after the first date I had with her. But the beer and the band were good.

[FLPhotoCatcher]

Back to the six-sided craters... Could the shape be caused by the atomic arrangement of the atoms that are hit first by the impactor? In other words, if you press atoms into a tight, flat layer, they should be arranged in a hexagonal pattern. As the shock wave expands, it expands faster in the six directions perpendicular to the flat sides of atoms. Maybe the areas of faster-expanding atoms vs slower expanding areas between them alternate as a kind of wave as the impactor continues to smash down.

[neufer]

[b][color=#0000FF]The [url=https://en.wikipedia.org/wiki/Giant%27s_Causeway]Giant's Causeway[/url] is an area of about 40,000 interlocking basalt columns on the northeast coast of Northern Ireland, the result of an ancient volcanic eruption.[/color][/b]

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Back to the six-sided craters... Could the shape be caused by the atomic arrangement of the atoms that are hit first by the impactor? In other words, if you press atoms into a tight, flat layer, they should be arranged in a hexagonal pattern. As the shock wave expands, it expands faster in the six directions perpendicular to the flat sides of atoms. Maybe the areas of faster-expanding atoms vs slower expanding areas between them alternate as a kind of wave as the impactor continues to smash down.

It would be unusual to have atomic crystalline formations larger than a human

[BMAONE23]

Click to view full size image

Another similar structure near mammoth mountain
And this place in Wyoming

Click to view full size image

[Chris Peterson]

Click to view full size image

Another similar structure near mammoth mountain
And this place in Wyoming

Click to view full size image

Structures like columnar basalts are, of course, related to atomic structure, but are not themselves crystals on a large scale. This is what I was talking about earlier with circular craters that degrade into square or hexagonal structures. It suggests a lack of isotropy in the material in which the crater forms. Many things can cause that- faulting, arrays of structured material like we see in columnar basalts, sedimentary layers. And that's just on Earth. Who knows what we might find on an asteroid?

[BMAONE23]

Here are the largest scale crystals I've ever seen

[Chris Peterson]

Here are the largest scale crystals I've ever seen

The largest single crystals I'm aware of, too. But you can have oriented geological structures extending over square miles, which can result in some crystal-like behavior over that scale.

[Beyond]

Here are the largest scale crystals I've ever seen

I remember seeing that place years ago. Isn't it also about 190° F in there?

[ta152h0]

my father bought a six sided amethyst in Minas Gerais, Brazil once. That was the way it came out of the ground. The only thing here is that nature sometimes is perfect and the guy that pulled this amethyst out got lucky

[neufer]

Tall mountains are interesting but what is the explanation for the hexagonal craters?

As an engineer, I'm reminded of the famous Devil's Postpile basalt columns that appear roughly hexagonal in cross-section. This is due to a "least energy solution" to differential cooling of the top versus the interior.

Suppose Ceres were to have developed a source of heat deep in the interior, e.g., from radioactive decay. The entire sphere might expand slightly and then eventually, as the heat source dissipated, shrink back. Craters that existed at the time might have become distorted into roughly hexagonal shapes as a result. Craters formed later would be "normal" looking.

.

• http://apod.nasa.gov/apod/ap141021.html

Click to play embedded YouTube video.

A new explanation for the hexagonal shape of lunar craters
van Dijk, Th.; Kistemaker, J.; Zeitschrift für Naturforschung, Teil a, vol. 36a, Apr. 1981, p. 410-412.

The possibility of impacts of large meteorites on the thin crust of the early moon accounting for the formation of the hexagonal lunar craters is discussed. Solidified basalts comprising a lunar crust of thickness 10 to 50 km characteristic of the earliest stage in lunar evolution are shown to have a large-scale hexagonal pillar structure, due to the effects of shrinkage. Results of experimental simulations of the propagation in this hexagonal pillar structure of the shock wave generated by the impact of a meteorite of diameter 10 km and mass 10 to the 15th kg on the lunar crust are then presented which demonstrate the pushing away from a central circular shock of pillars resting on a low-friction surface in a hexagonal pattern.>>

[BMAONE23]

Here are the largest scale crystals I've ever seen

I remember seeing that place years ago. Isn't it also about 190° F in there?

The main chamber contains giant selenite crystals (gypsum, CaSO4·2 H2O) which are some of the largest natural crystals ever found. The cave's largest crystal found to date is 39' (12 m) in length, 13' (4 m) in diameter and weighs about 55 tons. The cave is extremely hot, with ambient air temperatures reaching up to 136 °F (58 °C) (similar to Death Valley in summer) with 90 to 99 percent humidity (much UNlike Death Valley). The cave remains relatively unexplored due to these internal climate factors. Without proper protection, people can only stand about ten minutes of exposure at a time so wear your climate control suit.

[ta152h0]

those pesky buckyballs are everywhere