by MacRoos » Wed Feb 24, 2010 7:37 pm
To create the visible waves in the cloud when the rocket passed, is in my mind due to the presence of a very thin layer of ice crystals through which the rocket passed.
To create a halo and sundogs, the ice crystal faces in the cloud must be (somewhat) aligned, otherwise the random orientations would look just be a "regular" cloud, with no halos and sundogs. Such alignment of crystals could only happen in relatively undisturbed air, otherwise the crystals would be mixed up into random orientations, and the sundog would disappear. Therefore, if you disturb the air, as you would with a passing rocket, the waves in the air in which the crystals are suspended, would change the alignment of the crystals, as seen in the pattern.
For such a disturbance to be visible, the layer of crystal must be very thin. This can be seen by the shadow of the rocket visible in the video - it can only appear that way if the cloud "canvas" on which the shadow is "painted" is thin. If the cloud/crystal layer was thick, it would not cast such a distinct shadow.
As the layer is thin, it is possible to see the "waves" in the layer. These disturbances happen in all rocket flight, but the presence of such a thin cloud of ice crystals must be quite rare - therefore not seen often.
Therefore the pattern was created by a thin layer of ice crystals, undisturbed air, through which a wave-creating vehicle passed. Fantastic.
To create the visible waves in the cloud when the rocket passed, is in my mind due to the presence of a very thin layer of ice crystals through which the rocket passed.
To create a halo and sundogs, the ice crystal faces in the cloud must be (somewhat) aligned, otherwise the random orientations would look just be a "regular" cloud, with no halos and sundogs. Such alignment of crystals could only happen in relatively undisturbed air, otherwise the crystals would be mixed up into random orientations, and the sundog would disappear. Therefore, if you disturb the air, as you would with a passing rocket, the waves in the air in which the crystals are suspended, would change the alignment of the crystals, as seen in the pattern.
For such a disturbance to be visible, the layer of crystal must be very thin. This can be seen by the shadow of the rocket visible in the video - it can only appear that way if the cloud "canvas" on which the shadow is "painted" is thin. If the cloud/crystal layer was thick, it would not cast such a distinct shadow.
As the layer is thin, it is possible to see the "waves" in the layer. These disturbances happen in all rocket flight, but the presence of such a thin cloud of ice crystals must be quite rare - therefore not seen often.
Therefore the pattern was created by a thin layer of ice crystals, undisturbed air, through which a wave-creating vehicle passed. Fantastic.