This was my first opportunity to witness a lunar occultation of Saturn since 2007. Despite the UK’s currently patchy spell of weather, the clouds sort of stayed out of the way for the 21 August 2024 lunar occultation which took place in the early hour overlapping the start of dawn.

Ingress began under very hazy skies, a 22-degree halo visible around the Moon. Despite this, the planet was clearly visible and surprisingly steady for such a poor sky. Egress occurred under better conditions against a brightening dawn twilight.

The capture process was to record a multi-frame version of Saturn just prior to and after the event, with a similar treatment for the Moon. The positional data was recorded via a high frame rate capture running over the whole length of ingress and egress.

A final composite was produced using all of these components. Please bear in mind that any other ‘pretty’ images of the event will have required similar methodology as it’s not possible to stack an ever shrinking or growing Saturn properly, the huge dynamic range of the scene also proves a challenge even for modern cameras. The two positional reference frames used have been included in the shot.

Here the final result has been adjusted to better emulate the difference in brightness apparent through the eyepiece. It’s a big difference too which leads to interesting choices when recording the ingress/egress video. For this event I attempted to capture ingress with the Moon just shy of being over-exposed. For egress, I biased for Saturn, letting the Moon’s surface over-expose. Although I was confident of the emergence position of Saturn at egress, further confirmation was provided by the reappearance of Titan, a challenging site next to such a bright Moon.

The event was recorded from my home in Thornton, Leicestershire using a C14 at prime focus with Player-One Uranus-C and ZWO ASI174MM cameras, together with Astronomik L and R filters. Ingress frame 03:25:05 UT, egress 04:18:12 UT.