In the From the Vault series, I feature an older image which hasn’t been seen here before and I talk about the capture and processing and hopefully highlight why this image is special to me.
The feature image in From the Vault this week is an image and animation of Jupiter with Callisto in transit. Captured almost exactly 12 months ago, on the 31st May 2008, I was excited to be imaging on this morning because capturing a Callisto transit is quite rare due to the large and lengthy orbit of Callisto around Jupiter.
Callisto has a low albedo and while transiting Jupiter it actually looks like a shadow, but it’s the Moon itself! In some frames, albedo features on Callisto can be seen – one of the rare times I’ve been able to capture detail on the darkest Galilean Moon.
Click the image below to download and play the 18 frame animation that covers over 3 hours of Jupiters’ rotation.
Continue reading to see some of the best images from the animation, and to read more about the capture and processing of this series.
Seeing was quite variable during the 3 hours of capture, but for about 30 minutes it really steadied and the best image from the sequence is shown below, with Callisto in transit.
The image above also won the Solar System category at the recent SPSP17 star party astro-imaging contest.
The images were captured with my normal Planetary Imaging Equipment, the 12″ Newt and DMK21AU04. Each RGB image was recorded for about 45-50 seconds in each channel. I could record for longer in each channel because Callisto orbits slower than the rotation of Jupiter, so potential smearing of the Moon during transit wasn’t a problem.
The image above also shows the GRS, Oval BA (Red Jr) and the Little Red Spot (LRS) which met its demise in early July when it passed by the GRS and got torn apart.
The image was processed in Registax 5, AstraImage and Photoshop, and the animation was put together using Jasc Software Animation Shop 3.
Thanks for looking and for allowing me to share the memories of this image with you.