[X] My Assistant

[volcanopele]

The New Horizons images of Io that have come down over the last month have gotten me interested in Io again, and with Galileo images of Io. So I've decided to go back through and reprocess some of the color views of Io, particularly global views. I will post some of the more interesting ones here with the goal of rebuilding at least some of my Io website to host them in the long term.

The first view I'd like to present has a bit of a mystery. This is a two-frame, three-color mosaic of the Prometheus volcano from I27. The filters used are violet (in the blue channel), green (in the green channel), and IR-7560 (in the red channel). This mosaic has a resolution of 170 meters per pixel. I'm still working on the color registration (I'm doing all the present processing in Photoshop, so I hope no one minds).



Okay, so what's this mystery? Well, as I was attempting registration, I noticed something funny. I noticed this odd rainbow-colored patch to the southwest of Prometheus Patera. When you flip through the individual color frames, as you can see in the animation linked to below, you can see that this feature is actually a dark feature that moves from southeast to northwest from frame to frame. So what is this feature? The frames are separated in time by about 17 seconds. Could it be an optically thick...chunk in the plume? Any other...sane thoughts? Just thought I would throw this up there.



Well, I hope to post additional Io images over the next few days.

EDIT: I have uploaded a new version of the Prometheus mosaic and have updated the version in this post.

[elakdawalla]

Well, I've messed about with some Galileo images and I've come to the conclusion that attempting to get the color "right" in some technical way, like transforming the coordinates in CIE space, is just silly if I'm not working with calibrated data to begin with. And it looks like the only way to calibrate the Galileo images is to use ISIS, which I don't have access to. So I think I'll probably go back to my old method, which is just to combine filters willy-nilly, and make no claims as to the "true"ness of the color, and send people to Bjorn's website if they want a more rigorous idea of the true colors of Io.

For no reason at all, here's a global view from I24, with the green and violet mixed into the blue channel as Bjorn suggests.


--Emily