In the October 2021 issue of WGN, the journal of the IMO, it was suggested meteor observers submit observations from meteor showers with moon light present. Moonlight, something must of us meteor observers try to avoid, significantly affects how many meteors you can see. The aim of the project is to:
- obtaining complete activity profiles of shower (maxima)
- deriving reliable peak data for events occurring under poor conditions
- improving value of daytime shower data (twilight observations)
- determining the effect of sky background illumination quantitatively
This years Geminids offered a good chance to do that as will the 2022 Perseids. I reported on two showers:
Geminids (GEM)
Wasn’t planning on going out but the weather was ok and the chance for an hour in real dark skies was too alluring. So I went to the Flint Hills to observer the Geminids on 12/13. The hour from midnight to 1am had the sky full of moisture, thin bands illuminated by the moon. Moon was about 79% illuminated and I recorded 34 GEM even with that, bit surprising. As the moon got lower in the sky more and more meteors were visible. Total GEMs counted during nearly 4 hours observing was 190, a bit surprising. Temperature was so mild I could observer for long periods. The last hour or so the sky was nice and dark, well worth the trip. Clearly the Geminids are so strong they power through moonlight.
Ursids (URS)
The Ursids are not a very active shower but it certainly would be heavily affected by the strong moonlight. I did not travel for this opting to observer from my local area. The nearly full moon was out so why bother going anywhere! I got up early and observed starting about 03:45 on the 23rd. Cold morning but crystal clear. The moon was very strong being nearly overhead and 85% illuminated. I’ve never observed in such a moon light sky. Saw very few meteors, just two URS, with the sky around magnitude 4 naked eye limit.