About a year ago we had the 1st #covidlockdown in Germany

I'm the stay-home homeschooling dad - my wife is a medical doctor

But I could work @ night which I do often anyway

I did measure the night sky brightness and found it had decreased compared to before lockdown (1/12)
so in March 2017 it was less bright than in 2020 (see figure for zenith brightness)

this is surprising because we would expect light emission and #lightpollution to increase like shown in the paper we co-authored with @skyglowberlin and others


using night-time light satellite time series data (VIIRS DNB) we saw an increase in most major towns along the route we measured

you can check such data with @skyglowberlin tool:


this was what we eexpected (3/12)
however, we saw a decrease in #skyglow #lightpollution using all-sky cameras

how is that possible? (4/12)
well we strongly believe that it is due to reduced air traffic mainly and other reduced light emissions that the satellite cannot pick up

a group @DLR_de showed that there are less contrials when air traffic reduces so drastically as in #lockdown

dlr.de/content/en/art… (5/12)
airport statistical data showed that air traffic in #berlin decreased remarkably in March 2020 (−46.5%) compared to March 2019

April 2020 almost no air traffic was present compared to April 2019 (−93.2%).

our results are backed up by findings by @pmisson @cefalopodo @jon_bennie @KevinJGaston and others which draw a similar conclusion

(although they cite our work in a special way... 😉)


what does that mean?

do we need a #pandemic or a #lockdown to fight #lightpollution? Should all air trffic be banned?

Certainly NOT!

but #airpolluton goes hand in hand with star visibility (also in regions w/o #lightpollution)

because of reduced light scattering

this was shown by many papers like this one here for example:


so clean air goes hand in hand with better star visibility and reduced light pollution

and should become a part of the #darksky agenda

lets hope that despite this pandemic and those perpetual lockdowns are surely annoying us and making us sick

that we learn some things from this whole global crisis

and a big hail to all #womeninscience because I belong to a minority

mostly women suffer from childcare burden in this pandemic

"75% of women reported feeling stressed, compared with 59% of men."

see here



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