Jan 30

ISS near Moon flyby – excellent conditions

Mosaic photo of Moon combined with the International Space Station photo


Lately I am very busy with building a new platform on youtube tailored for hungarians. There myself and other space enthusiast friends we try to deliver as many space related news as possible, giving a helping hand for those who doesn’t speak english. Also part of my mission is to make people fall in love with the International Space Station (ISS).

Here is the original live stream – seconds away from the near flyby


A great opportunity came up a short while ago – a near Moon ISS flyby opportunity. I could see the station zoom past near the northern lunar limb from my own garden. So I have decided to stream it live on my own language. I must say it was such a pleasure to wait for this event with 300+ people also watching it! I do not have to mention that weather made it somewhat more difficult. Total clear sky all the way up to 15 mins left till the event. Then clouds appeared from nowhere, staying for a while. I saw it will be a short visit, roughly 3-5 mins prior to the flyby they nicely left and clearer once again giving free way for fun!


The screenshots above show the flyby predictions (top 2 screenshots from Heavens Above, bottom 2 are from ISS Transit Finder website). This was a difficult call, since Calsky is not around it is hard to find out where one needs to be unless one chooses the centreline. It was clear that I was outside the edge lines. The map with a blue corridor (from ISS Transit Finder) shows where one needs to be to see ISS crossing the lunar disc right in the center. The top and bottom lines parallel with centreline are marking the edge lines. If you are there ISS will may kiss the edge of Moon.
(or predictions visit this page)

It was clear that from my location ISS will appear slightly off the lunar limb. The question was that how far away it will appear. Luckily my estimates seemed to be correct and I could squeeze into my field of view (FOV) a bit of the lunar surface and ISS appeared in the center of FOV.


The photo above is a composite one. I had to first combine all the frames with ISS on them. When I did that the lunar surface was blurred. So I used a method commonly used in planetary imaging called stacking. This was one can combine even thousands of frames to enhance the overall sharpness, contras and in general the look of the final image. Once that was done, I combined the ISS frames with the lunar surface and voilá!

I also had the idea to keep on imaging the lunar surface and I might be able to make a lovely composite photo of the stitched lunar mosaic with the best ISS frame. This way one can see the whole event from a ‘farther distance’ (photo below) with a widened perspective.

What came as a nice surprise is how nice details can be observed on ISS. Even on the photos above you can see quite some details on the Space Station, most importantly the SpaceX Resilience Crew Dragon spacecraft, the one was used by Crew-1 mission. It is docked to the forward docking port of Harmony module.


When I did a separate processing approach focusing on the ISS only the result surprised me. Mainly because this whole event was captured in prime focus! I certainly did not expect details like these. Below you can see a stacked photo and also an endless animation from the frames.




Skywatcher 250/1200 Flextube dobson telescope
Zwo ASI224MC camera
TMS-Astro eq platform


If you like what I am doing and you might consider some kind of support, please visit my Patreon website.

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