I’ve never attempted to photograph this gas giant… our largest planet. It had been so long since I tried to take a picture of a planet that I really wasn’t sure I’d remember the steps. The planet was set to transit around 10:45pm at around 37° altitude, so the seeing was challenging despite being a beautiful night. You can see (left to right) Io, Europa, and Ganymede visible in orbit… these are 3 of the more well known siblings of Jupiter’s 79 moons. Fun fact: Ganymede is the largest moon in our solar system. I’m looking forward to trying this again when Jupiter and Saturn are higher in the sky, but I’m pretty ok with this first attempt!
I made another run at Jupiter last night. Mistakes were made.
Most of the data I accumulated during my session prior to transit is not usable in any way. Well, I did make a little GIF of the planet rotation that I’ll put in the comments, but basically it is mush. My plan poorly executed was to image through a 5x barlow to stretch the limits of the equipment I could bring to bear, but the gas giant remaining at low altitude (less than 37° at transit) and poor atmospheric seeing made this unrealistic. Every turbulent thermal mixing and tiny gust of breeze is amplified massively when shooting in this configuration. I took a series of 9 imaging runs with the barlow in place where I had planned to measure and derotate the result of each set and then stack them together. /sigh This is how we learn.
Fortunately, I did a single series after removing the 5x barlow with the native OTA and only an ADC (Atmospheric Dispersion Corrector) in-line with the planetary imaging camera. I tried to calibrate with the ADC, but the conditions were just too poor to get a good delta, so consider its use inconsequential for this image. This is the best half (ranked and weighted) of 10,000 frames imaged at 2350mm f/10, pre-processed/centered, debayering, image registration, deconvolution, and wavelet transformation applied, cropped and color adjusted. You can see (in order from left to right) Io, Europa, and Ganymede in frame, but Callisto was just out of frame to the right. I haven’t really figured out how to expose for the planet and the moons at the same time, but maybe people do the moons separately and then create a composite. Something for another day.
I still want to map and derotate a series of images over a longer acquisition window to see how that improves surface detail, but I think I’ll do it next time without any optical attachments to get practice with the post-processing workflow. It feels bad to throw away data… because that represents time invested that could have been used productively on something else. I do want to image with additional magnification and with a higher resolution sensor, but those are pushed down the priority list at this point.