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Unknown Dark Material on Mercury (APOD 2009 July 6)

Posted: Mon Jul 06, 2009 12:54 pm
by neufer
http://apod.nasa.gov/apod/ap090706.html wrote:
Explanation: What is that strange material on Mercury? When flying by Mercury last October, the robotic MESSENGER spacecraft imaged much of the solar system's innermost planet in unprecedented detail. As common in science, new data bring new mysteries. Pictured above on the lower right, a large crater -- about 100 kilometers across -- has unusual dark material of unknown composition near its center. The material's darkness does not appear to be caused by shadows, as the Sun was near zenith when the image was taken. One origin hypothesis is that the dark material was uncovered from beneath Mercury's surface during the impact that created the surrounding crater. If so, the composition of the dark mound might be similar to the composition of some mysterious dark rings also recently discovered on Mercury. Alternatively, the dark material could be related to an unusual composition of the impacting rock.
Unknown Dark Material : where The Thing from Another World landed:

Image

The Thing from Another World (1951)

Re: Unknown Dark Material on Mercury (APOD 2009 July 6)

Posted: Mon Jul 06, 2009 2:22 pm
by orin stepanek
It does have an interesting shape. I would like to see more pictures of it. maybe when Messenger gets into orbit; there will be better views of the dark material. :? makes one wonder what material Mercury may be made of or have in it. :shock:

Orin

Re: Unknown Dark Material on Mercury (APOD 2009 July 6)

Posted: Mon Jul 06, 2009 2:56 pm
by simonbrueck
Looking at the other craters, it is apparent that there are shadows. The dark material - in my view - qould be easily explained by a steeper hill throwing a distinkt shadow. The sun does not appear to come from the zenith and mercury´s curbature is not sufficiently narrow to hold up the view, that the craters nearby have shadows and th "dark material" can be straight below the sun. :)

Re: Unknown Dark Material on Mercury (APOD 2009 July 6)

Posted: Mon Jul 06, 2009 3:02 pm
by neufer
simonbrueck wrote:Looking at the other craters, it is apparent that there are shadows. The dark material - in my view - could be easily explained by a steeper hill throwing a distinct shadow. The sun does not appear to come from the zenith and mercury´s curvature is not sufficiently narrow to hold up the view, that the craters nearby have shadows and the "dark material" can be straight below the sun. :)
http://www.youtube.com/watch?v=xi8-g2Me8k0

Image

Re: Unknown Dark Material on Mercury (APOD 2009 July 6)

Posted: Mon Jul 06, 2009 4:29 pm
by emc
I think there's a pony in there somewhere...

Re: Unknown Dark Material on Mercury (APOD 2009 July 6)

Posted: Mon Jul 06, 2009 7:13 pm
by Loco
The dark material .. could it be Harmonium poo? I know that Harmoniums in their current stage of evolution are not known to poo, but perhaps back in their ancestral days they filled in a few craters.

For those who do not know Harmoniums: Wkipedia: "Harmoniums are, according to The Sirens of Titan by Kurt Vonnegut, the only form of life on the planet Mercury. Harmoniums are paper-thin cave-dwellers that feed on nearly undectable vibrations in the planet, described as "Mercury's song." Harmoniums are kite-sized and kite-shaped, and reproduce asexually by flaking off in a manner not unlike dandruff. They have only the sense of touch, and also rudimentary telepathic powers capable of only two messages: "here I am, here I am, here I am," and "so glad you are, so glad you are, so glad you are."

Harmoniums are a semi-transparent blue, making the yellow walls of Mercury appear aquamarine beneath them. When they die, they shrivel up like dried fruit. They can die from feeding off too much vibration."

If you can't believe Vone's gut what can you believe?

Re: Unknown Dark Material on Mercury (APOD 2009 July 6)

Posted: Mon Jul 06, 2009 11:55 pm
by aestival
Just looks like something hit at really low, tangential velocity, and was left sitting on the surface -- heck, even looks like it left a bit of a trail on the way in.

Re: Unknown Dark Material on Mercury (APOD 2009 July 6)

Posted: Tue Jul 07, 2009 1:39 am
by orin stepanek
The thing that gets me about the dark spot is that it is almost symmetrical; almost arrowhead shaped. The white spots are almost the same on the left and the right. Maybe they're not even part of it; but kind of looks like it could be. I think it is probably a meteoroid of some sort. 8)

Orin

Re: Unknown Dark Material on Mercury (APOD 2009 July 6)

Posted: Tue Jul 07, 2009 2:06 am
by apodman
aestival wrote:looks like something hit at really low ... velocity
Correct me if I'm wrong, but in the absence of atmosphere, rockets, or something else to provide braking, I believe you can't hit a planet from outer space with less than that planet's surface escape velocity, which in the case of Mercury is about 4.3 kilometers (about 2.7 miles) per second - which is not "really low velocity" according to most major league pitchers and traffic cops.

Re: Unknown Dark Material on Mercury (APOD 2009 July 6)

Posted: Tue Jul 07, 2009 2:28 am
by neufer
apodman wrote:
aestival wrote:looks like something hit at really low ... velocity
Correct me if I'm wrong, but in the absence of atmosphere, rockets, or something else to provide braking, I believe you can't hit a planet from outer space with less than that planet's surface escape velocity, which in the case of Mercury is about 4.3 kilometers (about 2.7 miles) per second - which is not "really low velocity" according to most major league pitchers and traffic cops.
Who's to say there wasn't rockets or something else to provide braking.
  • -------------------------------------------
    _THE THING FROM ANOTHER WORLD_ RKO 1951
    . Screenplay by Charles Lederer
    .......................................
    . NIKKI
    . (opening the note book in
    . her hand and reading from it)
    .
    November 1, 11:15 p.m. Sound detectors
    registered explosion due east. 11:18 p.m.
    magnetic dial revealed twelve point three
    deflection. Such deflection possible only
    if a disturbing force equivalent to 20,000
    tons of steel or iron ore had become part
    of the earth within fifty mile radius.
    .
    . HENRY
    That sounds like a meteor, doesn't it?
    .
    . CARRINGTON (amiably)
    Yes, very much. Except for our photographic
    plates. Our telescopic cameras were working
    last night. Here is the film taken between
    11:12 and 11:15. Let Captain Henry see it, Bill.
    .
    . Stone switches on a light in a moviola box
    . and runs a strip of film slowly through it.
    . Captain Henry looks into the box.
    .
    . CARRINGTON
    You will note the small dot low on the film.
    It is moving from west to east. At 11:14
    the dot moves upward. At 11:15 it drops to
    the earth and vanishes. A meteor might move
    almost horizontally from west to east, but
    never upward. If the traveling object caused
    the explosion we picked up, it is in the ice
    48 miles from here. The sound reached us
    four minutes after the object's disappearance.
    This gives us the approximate distance from here.
    .
    . HENRY (frowning)
    Twenty thousand tons of steel
    is a lot of metal for an aeroplane.
    .
    . CARRINGTON
    For the sort of aeroplane we know, Captain.
    -------------------------------------------

Re: Unknown Dark Material on Mercury (APOD 2009 July 6)

Posted: Tue Jul 07, 2009 2:33 am
by bystander
aestival wrote:Just looks like something hit at really low, tangential velocity, and was left sitting on the surface -- heck, even looks like it left a bit of a trail on the way in.
apodman wrote:Correct me if I'm wrong, but in the absence of atmosphere, rockets, or something else to provide braking, I believe you can't hit a planet from outer space with less than that planet's surface escape velocity, which in the case of Mercury is about 4.3 kilometers (about 2.7 miles) per second - which is not "really low velocity" according to most major league pitchers and traffic cops.
I think aestival meant to imply a low incident angle, which might have some merit. It looks like the object could have entered from just above the lower right corner, low to the horizon (like Kaguya), and left something like a wake behind it.

Re: Unknown Dark Material on Mercury (APOD 2009 July 6)

Posted: Tue Jul 07, 2009 3:45 am
by neufer
bystander wrote:
aestival wrote:Just looks like something hit at really low, tangential velocity, and was left sitting on the surface -- heck, even looks like it left a bit of a trail on the way in.
I think aestival meant to imply a low incident angle, which might have some merit. It looks like the object could have entered from just above the lower right corner, low to the horizon (like Kaguya), and left something like a wake behind it.
Comets are DIRTY iceballs.

After all the ice evaporates there would be a lot of CARBONACEOUS SOOT
left behind that won't be getting washed away by weather.

Image
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http://antwrp.gsfc.nasa.gov/apod/ap001105.html
http://tinyurl.com/mz5oo4
http://tinyurl.com/npq4xj
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http://tinyurl.com/lyutc4

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http://en.wikipedia.org/wiki/Iapetus_(moon) wrote:
<<In the 17th century, Giovanni Cassini observed that he could see [Saturn's moon] Iapetus only on the west side of Saturn and never on the east. He correctly deduced that Iapetus is locked in synchronous rotation about Saturn and that one side of Iapetus is darker than the other, a conclusion later confirmed by larger telescopes. The difference in colouring between the two Iapetian hemispheres is striking. The leading hemisphere and sides are dark (albedo 0.03–0.05) with a slight reddish-brown coloring, while most of the trailing hemisphere and poles are bright (albedo 0.5-0.6, almost as bright as Europa). The original dark material is believed to have come from outside Iapetus, but now it consists principally of lag from the sublimation of ice from the warmer areas of Iapetus's surface. It contains organic compounds similar to the substances found in primitive meteorites or on the surfaces of comets; Earth-based observations have shown it to be carbonaceous, and it probably includes cyano-compounds such as frozen hydrogen cyanide polymers.>>
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Re: Unknown Dark Material on Mercury (APOD 2009 July 6)

Posted: Tue Jul 07, 2009 7:43 pm
by Loco
So, Lapetus might be a source for the product this company sells. http://www.fao.org/docrep/005/ad030e/AD030E10.htm