Planet Four Talk

Chronology?

  • wassock by wassock moderator

    Screenshot of HiRise image .http://hirise-pds.lpl.arizona.edu/PDS/EXTRAS/RDR/ESP/ORB_020700_020799/ESP_020742_0925/ESP_020742_0925_RGB.NOMAP.browse.jpgDecember - 2010 image.

    Several examples of this on the bigger image. I am seeing a narrow dark fan overlain with a wide bright fan (seemingly from the same source) which makes the long one under it grey. the bright fan then has more recent dark fans from other sources on top of it.

    Alternate visions anyone?

    enter image description here

    Posted

  • mschwamb by mschwamb scientist, translator in response to wassock's comment.

    There was another example like this, that came up in discussion that Candy commented (DPF0000dpl).

    Cheers,

    ~Meg

    Posted

  • wassock by wassock moderator

    I think these are subtly different in that there appear to be dark fans which are overlain by the brighter material which in it's turn has more dark fans on top. If this interpretation is correct then whatever is in the bright fans is different from whats in the dark. the bright stuff produces a different shaped fan and interacts with the surface differently. And it only affects some fans which points to it being related to the fan mechanism rather than being either a atmospheric effect or surface melting.

    Posted

  • mschwamb by mschwamb scientist, translator in response to wassock's comment.

    Yes, but I think that's just timing, and probably same thing is going on in both images, just ordering of the processes swapped.

    Cheers,
    ~Meg

    Posted

  • wassock by wassock moderator

    but the dark fan under the white fan is still essentially dark. The white fan thus must either be made of something different or interact with the surface differently. the subsequent dark fans dont notice the white fan and look the same as if they were on the surface. If they do form in that order that is.

    If the light is fresh frost/remelt/particles sinking why is the same effect not happening to the dark bits?

    NB not raising these expecting a difinitive answer here just trying to see if these are valid questions.

    Posted

  • p.titchin by p.titchin

    just an amateur player in your project, but I notice repeatedly a lack of certainty in the way our images are presented and exactly what colours are 'true'. I noticed in several references to images ( including the planet four blog) that quite bright blue fans and blotches are just referred to as 'dark' . This worried me when I looked through my collection of blue fans as I realised that until I had a common reference for the colours, I could not really go any further. If 'blue' and 'white' are different in others' images, and our beautiful rare blue is just 'dark', then 'quo vadis'?

    -Pete

    Posted

  • mschwamb by mschwamb scientist, translator in response to wassock's comment.

    Well I believe it is, it's just which is fresher. So the white fan could be frost that first appeared from the vent and later in the day the dark fan was created. Or the white fan is a much older fan and so the particles have sunk, but the dark fans are much fresher so most of their material is still on the surface of the ice so it looks much darker.

    ~Meg

    Posted