01 January 2026

Jupiter and Ganymede

Jupiter, with one of its moons, Ganymede, casting its shadow onto the planet. (30/12/2025)

At last, we had another clear night! The moon was almost full, and I was surprised how much its brightness swamped out the light from stars I had come to know as friends, making navigation around the night sky more difficult. However, there was no mistaking Jupiter, especially as it was nearing opposition. 

Now, this is not the best shot of Jupiter you will ever see, but the exciting thing is that I managed to capture Ganymede and its shadow on the planet. Ganymede (the largest moon in the solar system) is that feint, small blob standing just separate from the disc of the planet in the image's top-left. The shadow is the 'hole' in the disc of the planet.

I'm still learning how to image planets (and everything else, to be honest) but I am nevertheless quite pleased with what I achieved before the cold rendered my fingertips unusable! This image is the result of stacking the best nine frames out of 29 taken with my mobile phone mounted at the eyepiece of my telescope.

Equipment

Telescope: Sky-watcher 130PDS on EQM-35 equatorial mount with SynScan GoTo
Camera: Samsung Galaxy A41 phone.
Processing Software: Siril with Starnet++, GIMP

Exposures

9 out of 29 jpeg auto exposures at ISO 100