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

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Expand view Topic review: APOD: An Unusual Mountain on Asteroid Ceres (2015 Jun 30)

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

by ta152h0 » Tue Jul 07, 2015 5:59 pm

those pesky buckyballs are everywhere

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

by BMAONE23 » Tue Jul 07, 2015 3:56 am

Beyond wrote:
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.

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

by neufer » Mon Jul 06, 2015 7:06 pm

dlw wrote:
pdtx wrote:
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.
.
Click to play embedded YouTube video.
http://adsabs.harvard.edu/abs/1981ZNatA..36..410V wrote:
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.>>

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

by ta152h0 » Mon Jul 06, 2015 4:39 pm

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

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

by Beyond » Mon Jul 06, 2015 4:01 pm

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

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

by Chris Peterson » Mon Jul 06, 2015 3:43 pm

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.

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

by BMAONE23 » Mon Jul 06, 2015 3:41 pm

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

by Chris Peterson » Mon Jul 06, 2015 4:05 am

BMAONE23 wrote: Another similar structure near mammoth mountain
And this place in Wyoming
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?

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

by BMAONE23 » Mon Jul 06, 2015 3:49 am

Another similar structure near mammoth mountain
And this place in Wyoming

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

by neufer » Mon Jul 06, 2015 3:35 am

FLPhotoCatcher wrote:
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 :arrow:

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

by FLPhotoCatcher » Mon Jul 06, 2015 2:42 am

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.

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

by ta152h0 » Sun Jul 05, 2015 7:14 pm

" 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.

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

by neufer » Sun Jul 05, 2015 10:55 am


geckzilla wrote:
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").

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

by geckzilla » Sun Jul 05, 2015 7:10 am

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.

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

by neufer » Sat Jul 04, 2015 10:40 pm

ta152h0 wrote:
Pioneer 11 would be quite a story " and in this glass case is Pioneer 11 "
  • Lotsa luck retrieving that!
https://en.wikipedia.org/wiki/Pioneer_plaque#Criticism wrote:

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.">>

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

by ta152h0 » Sat Jul 04, 2015 9:52 pm

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

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

by neufer » Sat Jul 04, 2015 10:43 am


ta152h0 wrote:
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.

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

by ta152h0 » Sat Jul 04, 2015 4:30 am

that collision would be more interesting than a million year journey around Ceres. Like messenger on Mercury. The locals are etting off fireworks here

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

by neufer » Sat Jul 04, 2015 3:06 am


ta152h0 wrote:
Is this object interesting enough to conduct an EROS style landing before the fuel runs out ? Near or on the bright spots ?
Ceres's surface escape velocity is 0.51 km/s
and it's "surface" orbital velocity is 0.36 km/s [= 0.51/sqrt(2)].

Dawn's weak ion propulsion is only capable of slowly spiraling down to a ~0.36 km/s collision with the mountain.

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

by ta152h0 » Sat Jul 04, 2015 12:31 am

Is this object interesting enough to conduct an EROS style landing before the fuel runs out ? Near or on the bright spots ?

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

by Joe New » Fri Jul 03, 2015 1:38 am

I'll remedy the overlooking of one vital step, indispensable to history, by our scientific community: I hereby declare the Ceresian summit "Mount Marmaduke."

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

by DavidLeodis » Wed Jul 01, 2015 5:13 pm

It's a very interesting object. Viewed in the 'upside down' orientation that the image was released it looks like something forming from a drip. Perhaps it's a giant stalagmite! :wink:.

Re: APOD: The BRIGHT SPOTS!!!

by Interociter Operator » Wed Jul 01, 2015 3:21 pm

Never mind the mountain!!!
What does spectroscopic-analysis show those BRIGHT SPOTS to be made from!?!?!??!?!

Also - Even if the ship can't be pointed back at Earth directly, what is the math behind how many times it will accidentally be pointed at earth as it slowly tumbles around the planet. If even a broken clock tells the correct time twice a day, how frequently, and when, will the ship be pointed in the right direction without our assistance?

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

by Nitpicker » Wed Jul 01, 2015 1:43 am

Chris Peterson wrote:
pdtx wrote:Tall mountains are interesting but what is the explanation for the hexagonal craters?
Craters are round when they are created (outside of some special cases like extremely oblique impacts). The most likely reason for non-round craters is subsequent slumping of the crater walls. We see that when there is some sort of structure in the material where the crater lies- faulting, patterning, or other non-continuities. The squared-off shape of Meteor Crater in Arizona is a good example, caused in that case by faulted rock.
The article available from this link:
https://journals.uair.arizona.edu/index ... view/15304

... suggests that (at least for the 829 straight rims of the 269 polygonal Martian craters studied in the Argyre region) the "polygonality is not caused by degradation, but originates from the cratering process itself". The statistical distribution of the strikes (the geological term for the bearings) of all these straight rims, indicates an underlying and preexisting geometry in the geological structure.

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

by hoohaw » Tue Jun 30, 2015 11:55 pm

" There's really no difference between an asteroid and a dwarf planet when we're talking about bodies in the asteroid belt."
And, if you cut an asteroid in two, you get ... two half-asteroids?

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