Cloud shadows on Jupiter?, Voyager 1 images Options

[Bjorn Jonsson]

When taking a look at some of the Voyager images of Jupiter I noticed something interesting in Voyager 1 image C1638201.IMQ - possible cloud shadows. I haven't seen them before on Jupiter in any spacecraft images. Here is a flat fielded, cleaned up and contrast stretched version of C1638201.IMQ:



At this time Voyager 1 was imaging equatorial and southern latitudes not far from the terminator which is to the right in this image. The possible cloud shadows are especially noticeable at lower right and near the image center. These features are more subtle but still noticeable without any contrast stretch or flat fielding:



C1638201.IMQ is a clear filter image obtained on 1979-03-05 06:08:36. The distance from Jupiter is 567,000 km according to the Jupiter Viewer at the PDS Planetary Rings Node. This yields a resolution of ~5 km/pixel.

There are more images obtained at a similar time that also seem to show shadows although this is the best example I have noticed so far.

If these are indeed cloud shadows (I can't see how this could be anything else) they must have been noticed before (they aren't that subtle) although I don't remember seeing cloud shadows mentioned before on Jupiter.

By the way the Voyager datasets for Jupiter are in my opinion still very interesting despite the Galileo and Cassini images. The resolution is much higher than in the Cassini images and there is far better time lapse stuff from Voyager than Galileo.

[tasp]

Would that 3D process work on those images? Seems like if the shading was shadows, the software might do something, but IIRC, the software was designed for a solid surface, not a cloudscape . . .

Sorry, it's late and I am not sharp enough right now to find the right thread with the info.

[antipode]

Wow - that's neat. Certainly looks like just the tops are reaching a level where they glaciate. What are the clouds made of at that level?

P

[machi]

By the way the Voyager datasets for Jupiter are in my opinion still very interesting despite the Galileo and Cassini images. The resolution is much higher than in the Cassini images and there is far better time lapse stuff from Voyager than Galileo.

In fact Voyager images are better than Galileo images in terms of resolution. Best usefull images are at ~2.7 km/pix.

[machi]

One of the best images of Jupiter from Voyager 1. Resolution is 2.65 km/pix.
In this image are very interesting clouds, they looks like flying icebergs.

Attached thumbnail(s)

 

[Phil Stooke]

"Would that 3D process work on those images? Seems like if the shading was shadows, the software might do something, but IIRC, the software was designed for a solid surface, not a cloudscape . . ."

The software doesn't know what the surface is made of. Shape from shading certainly could do something with the clouds that show shadows. The varying shades among the background clouds may create artifacts, but albedo markings do that on solid surfaces as well.

Phil