Stickney Crater, sweep up radiation (APOD 10 Apr 2008)

[neufer]

http://apod.nasa.gov/apod/ap080410.html
http://antwrp.gsfc.nasa.gov/apod/ap000308.html
http://antwrp.gsfc.nasa.gov/apod/ap041120.html
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http://en.wikipedia.org/wiki/Phobos_(moon)

<<Around 1958, Russian astrophysicist Iosif Samuilovich Shklovsky, studying the secular acceleration of Phobos' orbital motion, suggested a "thin sheet metal" structure for Phobos, a suggestion which led to speculations that Phobos was of artificial origin.Shklovsky based his analysis on estimates of the upper Martian atmosphere's density, and deduced that for the weak braking effect to be able to account for the secular acceleration, Phobos had to be very light — one calculation yielded a hollow iron sphere 16 km across but less than 6 cm thick. In a February 1960 letter to the journal Astronautics, S. Fred Singer, then science advisor to U.S. President Dwight D. Eisenhower, came out in support of Shklovsky's theory, going as far as to state that "[Phobos'] purpose would probably be to sweep up radiation in Mars' atmosphere, so that Martians could safely operate around their planet".>>
......................................
Geological features on Phobos are named after astronomers who studied Phobos and people and places from Jonathan Swift's Gulliver's Travels. The only named ridge on Phobos is Kepler Dorsum, named after the astronomer Johannes Kepler. Several craters have been named.
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Crater _________ Named after
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Clustril Character in Gulliver's Travels

D'Arrest Heinrich Louis d'Arrest, astronomer

Drunlo Character in Gulliver's Travels

Flimnap Character in Gulliver's Travels

Gulliver Main character of Gulliver's Travels

Hall Asaph Hall, discoverer of Phobos

Limtoc Character in Gulliver's Travels

Reldresal Character in Gulliver's Travels

Roche Édouard Roche, astronomer

Sharpless Bevan Sharpless, astronomer

Skyresh Character in Gulliver's Travels

Stickney Angeline Stickney, wife of Asaph Hall

Todd David Peck Todd, astronomer

Wendell Oliver Wendell, astronomer
-----------------------------------

[Sputnick]

The mars moon photo http://antwrp.gsfc.nasa.gov/apod/astropix.html
shows "unexplained" streaks which look like grooves.
In a streak near the bottom left of the photo appears what looks like a round rock. Could this rock be travelling by rolling .. pushed by small centrifugul forces as the moon slowly wobbles .. if the moon slowly wobbles? The rolling rock would of course create the grooves as tracks if the surface of the moon is soft dust. A somewhat similar occurence happens to rocks on the raceway of the dried lakebed in the U.S. southwest as they travel and leave tracks (apparently by being pushed by strong winds after rains which turn the dried mud slick).

[JohnD]

Sputnick,
No atmosphere, so no wind on Phobos.
Phobos (and Deimos) tumbled in the past, but are tidally locked now and keep their same face turned to Mars, having leading and trailing sides. And if Coriolis forces could occur they wouldn't affect something as small as a boulder.
I think we've been here before, the last time Phobos pics were an APOD ( http://antwrp.gsfc.nasa.gov/apod/ap061203.html ).
See http://asterisk.apod.com/vie ... ght=phobos .

The explanation for the streaks is 'crater chains'. Not in the sense of "craterchains" who posts regularly here, and who believes in past interplanetary war, but in the same sense as the ending of the Shoemaker-Levy comet, that broke up into a string of lumps in the gravity field of Jupiter, as it spiralled in. Phobos passed through several such disintegrating objects (not necessarily comets) in the past. The components of the strings were so small and close together, that the result after aeons of time and in the low resolution of these superb pics appears to be grooves. The varying angles of the 'grooves' demonstrates the tumble that the moon had, before it locked to Mars.

The brown dust 'blowing away' from the crater to the left and below of Stickney is more difficult to explain. The caption suggest that similar brown material has slid down the inside walls of Stickney. Is it possible for the CoG of Phobos to be towards the other end of the moon, so it's sliding down from the small crater too?

JOhn

[BMAONE23]

Given the images here what is the likelyhood that:
a) Given the relatively dismall gravity on Phobos,
b) The relatively LOOSE compaction of the small moon's surface material,
c) the relative size of Stickney Crater,
d) The apparent linear features radiating out from Stickney
Could it be possible that the Stickney Impact was from a similarly loosely packed asteroid striking at a low relative velocity and, after breaking up on impact, due to the relative low ammount of gravity on Phobos, the resultant debris field continued to "roll/scrape" down the surface of the moon in the direction of impact and escape back into space??

[Sputnick]

The references provided discuss organic material on Phobos. I'm wildly open-minded enough about mankind's infinitesimal knowledge of lifeforms to believe possible (only a theory of course) that the 'rock' in the groove is a silicon creature and the organic material is its excrement .. possibly the creature is eating its way across the surface of the moon creating the grooves although I think the possibility of rolling rocks in an earlier history of that moon more probable. I'm sure we'll find life on the moon of Saturn on which are methane 'rainstorms', rivers, and lakes. I'm sure there is life in gaseous forms in nebula. I remember one of the first photos back from Mars (30 years ago?) which showed two items described as 'boulders' but on which I am sure I saw faces with pairs of eyes looking directly at the camera which of course would have attracted attention by its movement .. a pair of Armadillo like creatures probably composed mostly of silicon rather than carbon. Okay .. so now almost anyone reading this will think I'm nuts .. but I've been carying the nickname Sputnick for 50 years .. since I was 11. My curiosity in the sciences is great. Posibilities are as unlimited as the universe.

[JohnD]

Sputnick,
To be so openminded is commendable, but leaves you, er, open to the accusation of having a headful of vacuum! In astronomical terms (and in chemistry), 'organic' refers to any carbon based compound, not necessarily one formed or even decayed from an organism. Such compounds are found in interstellar dust clouds.
Please seek some evidence to back up your rather fantastic ideas.

BMA,
The grooves could certainly be due to linear impacts from debris from Stickney, secondary cratering, but observe - some 'grooves' are not radial to Stickney. Also, to cause such a large crater as Stickney, the impact must have been considerable. Debris would have been ejected at some speed, probably at far more than Phobos' escape velocity.
Experiment by dropping a heavy weight into dry sand or flour, and see how the debris flies away. There are a number of teacher's aids on this on the net; try the Nasa one: http://ares.jsc.nasa.gov/Education/acti ... raters.pdf

John

[eagle1210]

Phobos looks translucent in this image, like a dusty ice cube. Is it's composition known?

[Sputnick]

Genuine thanks for your informative reply, John .. and I admit a vacuum in my head which comes from lack of higher education - I'm a high school graduate only .. and that was a four year commercial program - but I scored Mensa in a Grade 11 I.Q., and my lack of higher education 'programming' allows me to think outside the box .. fantastic thoughts sometimes, I agree, but when we consider how totally self-assured some scientists are just before they are proven totally wrong, I prefer my style of thinking because its advantages could put new information to good use, whereas conventional thought tends to distort or ignore new facts which make the 'identity' of the scientist (or anyone else for that matter) insecure. A relatively recent example was when astronomers who had carefully measured the classes and distances of stars were proven somewhat mistaken in their calculations when the stars were discovered to be galaxies .. with error of course measuring in the billions of billions. Theories should never be taught as facts, and yet they are. When Europe first received reports of African wildlife (Giraffes and Zebras as examples) the descriptions were thought to be absurd. We barely recognize life forms on earth, so how much more open minded should we be about life forms outside our planet?

[JohnD]

Sput,
This a little off-thread, but your pride in ignorance may let you down one day.

Your picture of arrogant scientists, pushing through their wild theories is so far from the truth, that I have to ask you for a reference to the "stars discovered to be galaxies"!

And giraffe and zebras discounted? By whom? The Romans tried to use zebras as exotic chariot pullers and they knew the giraffe as the "cameleopard", which is the species name today. More distant lands were populated with the phoenix, the kraken, dragons and "men whose heads, Do grow beneath their shoulders" as Shakespeare wrote. The human imagination is all too ready to accept the fantastical and imaginary in weird beasts. All the more reason to apply Ocam's Razor and insist on evidence before belief.

We NEED mavericks, in science and technology, but those who make it through are those that have made a deep study of their subject and discovered new facts or flaws on old arguements. Irecommend that course of action to you, if you wish to make your mark.

Good luck!
John

[BMAONE23]

BMA,
The grooves could certainly be due to linear impacts from debris from Stickney, secondary cratering, but observe - some 'grooves' are not radial to Stickney. Also, to cause such a large crater as Stickney, the impact must have been considerable. Debris would have been ejected at some speed, probably at far more than Phobos' escape velocity.
Experiment by dropping a heavy weight into dry sand or flour, and see how the debris flies away. There are a number of teacher's aids on this on the net; try the Nasa one: http://ares.jsc.nasa.gov/Education/acti ... raters.pdf

John

The only problem with creating craters in sand on Earth and using this as a model for the creation of craters in the microgravity/vaccuum of space is that the craters are being created in sand on Earth and will only accurately reflect/model such an event, i.e an impact in sand by an impactor traveling through atmospheric pressure and in a constant 1g environment. There is no way to accurately model an impact of loose material into loose material in a vaccuum and being aaffected by microgravity without actually witnessing it. Computer models are only just that but without visual confirmation and field data gathering it is still just supposition at best.

[BMAONE23]

The references provided discuss organic material on Phobos. I'm wildly open-minded enough about mankind's infinitesimal knowledge of lifeforms to believe possible (only a theory of course) that the 'rock' in the groove is a silicon creature and the organic material is its excrement .. possibly the creature is eating its way across the surface of the moon creating the grooves although I think the possibility of rolling rocks in an earlier history of that moon more probable. I'm sure we'll find life on the moon of Saturn on which are methane 'rainstorms', rivers, and lakes. I'm sure there is life in gaseous forms in nebula. I remember one of the first photos back from Mars (30 years ago?) which showed two items described as 'boulders' but on which I am sure I saw faces with pairs of eyes looking directly at the camera which of course would have attracted attention by its movement .. a pair of Armadillo like creatures probably composed mostly of silicon rather than carbon. Okay .. so now almost anyone reading this will think I'm nuts .. but I've been carying the nickname Sputnick for 50 years .. since I was 11. My curiosity in the sciences is great. Posibilities are as unlimited as the universe.

Sounds like Phobos could be filled with an entire "Horta Culture"

[cherlin]

[quote="BMAONE23"]The only problem with creating craters in sand on Earth and using this as a model for the creation of craters in the microgravity/vaccuum of space is that the craters are being created in sand on Earth and will only accurately reflect/model such an event, i.e an impact in sand by an impactor traveling through atmospheric pressure and in a constant 1g environment. There is no way to accurately model an impact of loose material into loose material in a vaccuum and being aaffected by microgravity without actually witnessing it. Computer models are only just that but without visual confirmation and field data gathering it is still just supposition at best.[/quote]

Then we must get NASA to do it on the space station and stream it live on the Net. At last, a genuine scientific use for that boondoggle. ;->

"We'll be saying a big hello to all intelligent lifeforms everywhere and to
everyone else out there, the secret is to bang the rocks together guys."
--Hitchhikers Guide to the Galaxy, by Douglas Adams

[iamlucky13]

The secular accelleration of Phobos is a favored topic of a few posters here.

The problem was atmospheric drag couldn't account for the momentum change of a dense moon necessary for the magnitude of position change relative to the predictions that astronomers saw in Shklovsky's time.

It was later determined that tidal forces could almost completely account for the discrepancy.

The effect of Phobos' gravity on probes orbiting Mars have confirmed that it has a density of about 2g/cc, or about twice that of water and a little bit less than packed soil on earth.

[Sputnick]

John - Pride in ignorance? Perhaps. But pride in knowledge which is false can be worse. At least if someone knows they are ignorant they may be persuaded to become more open minded .. but if they think they know what they know not their professional status may prohibit them from reconsidering. You mention Roman times, but the Greeks and Romans were highly advanced thinkers (the Greeks having measured the circumference of the earth for instance) compared to the Europeans of the post dark age, flat earth era of which I mentioned .. the era of world conquest by the europeans, who, I will say, were superior to any other people in only one aspect, that of having firearms. Nevertheless, they wrote the history of which I spoke in which descriptions of African animals were met with ridicule .. No reference possible as my reading has been avid and broad (astronomy being one of many interests) but not in pursuit of any kind recognition which requires substantiation. For instance, I can say that regular commerce was conducted between pre-Columbus America and the empire situated on the Atlantic shore of Africa near the entrance to the Meditarean, but I can only say I read it in a history book in the public library. I can say that the wheel was known and used in children's toys in the Americas before Columbus, but only through the same reading. I can substantiate almost nothing of which I speak .. but that's not important to me .. what is important is the exchange of ideas and knowledge, and the investigation of possibilities .. and only for the enjoyment of my mind, the well being of my body and spirit, and possible benefit for others. To be recognized by others as correct means nothing to me unless it is in something which could bennefit their lives. Knowledge is too vast, possibilities are too wide, and mankind's general understanding of reality appears to be at a level similar to our knowledge of dark matter, which may simply be another mathematical error .. but as a possibility dark matter is interesting to explore .. as is the possibility of our being able to walk through 'solid' walls with our 'slid' bodies. Perhaps a tuning fork set to the right frequency?

[astrolabe]

I don't which direction Phobos is orbiting but if it's to the right it looks like it's been slowly collecting red dust, maybe extraterrestrial debris from Martian superstorms over eons. So things get covered and "fall" behind the sdge of crater rims and avalanche inside. Doesn't explain the grooves though in the "undusted" areas. Could explain the reddish trails of the smaller creters in those grooved areas however.

[astrolabe]

P.S. Of course when sand is heated to thousands of degrees (3?) it melts to form glass so the reflective silvery deposits if that be the case could be relatively smooth enough that dust might not adhere as well when the object passes through it.

[JohnD]

astrolabe,
Think about it!
There is no atmosphere on Phobos.
Snow or sand forms drifts behind objects, becausde the wind velocity is less and it can drop out of suspension in the air.
In the absence of any wind, an obstruction would collect dust in front of it.

John

[Sputnick]

That big volcano on Mars must have expelled a lot of dust to very high altitudes. Phobos is volcanized?

John D - no atmosphere, true; but an object moving through clouds of dust suspended in space would be its own 'wind', and (let's factor in the theory of dark matter here as an interesting poetential cause with interesting possible effects) the effect would be/could be similar .. even with 'swirls' of dust possibly created by electromagnetic fields generated by the dust particles' proximity to each other's movement. Effects in space can take fantastic lengths of time, or fantastically short durations of time. We really can't closely compare effects on earth with effects in space. To see some of the power of the unsuspected, some night while in bed in your dark bedroom, cover your head with your blanket and bedsheet, lift the covering high by bending your knees upwards (creating a 'tent') and run your fingers lightly over the inside of your bedsheet. If conditions and material are right you will be amazed to find yourself inside an electrical storm.

[JohnD]

Sputnik,
"an object moving through clouds of dust suspended in space would be its own 'wind' "
Are you teasing me, or do you really believe that?

Has your extensive reading extended as far as Newton's Laws of Motion?First Law: Any object will continue moving in the same direction, at the same speed unless a force acts upon it.
The only force acting on a dust mote in space is the gravity of nearby objects. That of other dust motes is too small to be significant, except over macrocosmic distances. That of distant objects will influence all the dust, not just one particle, so both of these may be discounted.

If a larger object moves so close as to pass through the cloud of dust, then the gravity of that object becomes significant. Dust motes will change their movement towards the object, in obedience to Newton One. But the influence of other dust motes will stay the same, very small indeed.
Dust that strikes the object may stay impacted or 'bounce' off. The change in direction and speed will be entirely in accordance with Newton One, Two and Three.

Now, where is the wind in that?
A 'swirl'of dust must be accelerated continuously to keep it in a circular or spiral orbit. That demands a constant force. Where does that come from? Unless the 'swirl' is an orbit around the large object, a situation that I do not think you need.

Sputnik,
I'm spending some time on you BECAUSE you are intelligent and interested. But you really have to acquire some background to contribute.
Oh, and I saw a storm of sparks the other night when I pulled a synthetic fibre shirt off, over my head and hair. Electrostatic force could be another force acting on dust motes, but in a stable situation, they will rarely strike each other so the opportunity for charge seperation is small. It will increase after the collision of the cloud with the large object.

John

[astrolabe]

Hello JohnD

Thanks for the input. I have been thinking about it.....honest! My statement did not mention "wind", nor did it even imply "swirl". I was persuing the idea as a more passive phenomenon than that. And not occuring in centuries but perhaps a coupla billion years or so. It does look as though a few craters to the right have filled up some, not to say that solar "wind" couldn't play a role as well. I would like to see the back side for comparison.

Even so, if one takes a bowl and sinks it into sand then builds up sand around the edge what happens? One gets a reasonably defined "peak" around that edge with sand "falling" into the center.....without wind!

I would also think that until a polar circumference is reached a sphere's leading side could collect matter over most of it to some degree

[Sputnick]

John D - I'm spending time on you because your thought processes need expansion - for instance, you have to eliminate the boundaries which prohibit you from realizing that matter (which is theorized to be merely dense energy, right?) has effect on all other matter in the immediate, galactic or universal neighbourhood. Your scale is made on earth instead of in the heavens (our friend Astrolabe has the right scale in mind) .. but even here on earth, have you not read about the european experiment in which a 'mirror' particle (neutron, electron, whatever it was I don't take notes) exhibited mirror behaviour to that of a particle manipulated in a laboratory (a hundred miles? Hundreds of miles? distant?) You ask for stubstantiation of my comments while I admit I have none - yet you make statements which you obviously consider authoritative ("the streaks are crater chains") without any reference to anything or anyone who supports your view. Your thoughts would be more valid if you said, "In my opinion the streaks are crater chains because ...." For my part I see absolutely no evidence that they creater chains .. the moon's composition obviously contains a lot of ice .. perhaps when the moon was closer to Mars, if it was, the impact created enough residual heat to cause water to flow in rivulets which caused the grooves - the gravity of Mars attracting the water.) for you to be so confidant in your opinions while the athors of the webpage under discussion say the streaks are mysteries show that you think too highly of your own opinions. However, you are an interesting character, and curious enough for me to attempt to enlighten.

[Sputnick]

No wind in space? There is solar wind of course - and there could also be dark matter wind, if dark matter exists; and I prefer to think of dark matter's possible flow as riverlike, or currents in an ocean - flowing water also builds 'drifts' similar to sand dunes - so Astrolabe's mention of dust deposits building up in drifts over billions of years is definitely possible .. and I think probable.

[astrolabe]

With respect due to all, I'm not the least bit trained in this field other than what I've seen and read because I have a passion for it. My thoughts and ideas may not be correct, but they're only my thoughts and ideas, and while mostly unfounded, I get to use this format to think out loud for a while which, of course, includes taking the risk of being wrong in public.

By the way, I just read a link off the APOD in question and there was mention of material that had fallen into craters, crater chains, and other interesting devices. But, alas, no mention of impect heat melting sand into glass! Oh well, NEXT!
.

[JohnD]

astro,
But you did say, "So things get covered and "fall" behind the sdge of crater rims and avalanche inside." If you did not have in mind a snowdrift, then I misunderstood.
Certainly there are plenty of pictures now from Saturn's moons of material that seesm to have been collected from orbit in the way you describe.

Sput,
"Mirror behaviour"? Do you mean quantum entanglement? What's that to do with Phobos?

Crater chains:
http://www.ingentaconnect.com/content/a ... rmat=print

And "water to flow in rivulets which caused the grooves". I'm speechless. The best theories for the origin of Phobos are either a captured asteroid or a conglomeration of orbital debris. http://sci.esa.int/science-e/www/object ... ctid=31031 Either way - no atmosphere, and now possibility for liquid water.

John

PS Sputnick. You keep sending me pms on these subjects.
Thanks, but I prefer to debate in public. J.

[JohnD]

Wel, wha'd'ye know!
Here's an excellent image of a 'wind' in space.
http://antwrp.gsfc.nasa.gov/apod/
But note that the 'cometary knots' have a diameter about the same as the oprbit of Pluto. It's a macrocosmic wind. Phobos wouldn't notice it, anymore than it notices the solar wind.

John