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The semester is off to a fast start; there are 7 students working on various projects, and their info should be posted shortly. It’s a good mix of interests (Physics, Biology, Electrical Engineering) and hopefully we will all learn a lot from each other. This is by far the most people we have had- the problem isn’t to make sure everyone is working on their own project, but scheduling lab times so we aren’t stepping on each other!

In the meantime, here’s a few composite images- one of Jupiter and the Galilean moons, and the other is the moon:

Some details: the upper image was created by first taking a picture (these were taken over a few months’ time) and then rotating the orientation of Jupiter/moons in each image to the same direction. The individual images were all ‘stacked’ together. and so the final image is a time series (time goes across), showing the movement of the moons over about 4 months of time. The lower image is also a composite taken over about 9 months to generate a time series showing how the shadowline moves across the lunar surface over one lunar cycle. It should be noted that the original size of the image (10500 X 10500 pixels) is too large to be displayed here- this image is 25% of the original.

It’s possible to extract a lot of information from these two images. The upper one could be analyzed to determine the orbital periods (and thus, distances) of the moons, if I can provide the time elapsed between successive images. Galileo could have done this (and he may have, I haven’t tried to find out). The lunar image can be used to measure surface topography (from the shadows cast from ridges and across plains), and some information about the various materials on the surface- the different reflectivities and spectral reflectivities can be used to distinguish dissimilar materials and the relative ages- the material ejected out of craters is older than the surface is covers.

it’s worth noting that Jupiter appears slightly different in each of the images- some variation is due to the post-processing, but some of the variation could be due to variations in the Earth’s atmosphere- whatever aerosols were present at the time, for example.


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