Tuesday, February 26, 2019

Can we get 2000 Globe at Night cloud-free observations this March?

I am currently preparing an analysis of the Globe at Night sky brightness data taken from 2006 up until today. It's really important that we do this, because the world is switching to LED lighting, and visual observations are the only way to really know if the sky is getting brighter or darker. The work is going well, but there is a problem - a problem I need your help with.

When Globe at Night started, it was a campaign that only took place in one month out of the year: March. Over time, Globe at Night expanded to allow people to do observations at any time during the year. This was intended to make it easier for people to take part. For example, if a teacher wanted to have his students make Globe at Night observations, it might make more sense to do it at another time during the semester. And some places frequently have cloudy weather, so an amateur astronomer might be disappointed if she can't make an observation one year.

However, I believe that the change to a full-year campaign had an unintended side effect of reducing the excitement and urgency of making observations. When observations can be made at any time, there is less urgency, less social media buzz, and it is therefore in some sense harder to motivate people to take part. Perhaps as a result, the total number of Globe at Night observations has been slowly dropping over the years. The bigger problem from my point of view, however, is that the number of observations taken in March has dropped even faster:

Annual number of Globe at Night observations. Observations in March are shown with a dashed line.
For the purposes of this plot, multiple observations from a single location in a single month are counted only once, and only cloud-free data is included.

This is a problem for me, because the reviewers of my paper might rightly ask whether it's fair to compare annual data taken during 2011-2019 to the March-only data from 2006-2010. Furthermore, can we really make strong conclusions about trends when there were thousands of March Globe at Night observations in the past, but only a few hundred in recent years?

For that reason, I'm asking amateur astronomers, light pollution activists, and citizen science promoters to help me promote Globe at Night this March. If we work together to activate our networks, can we get March participation back up to the levels it had when Globe at Night first started? Please help by sharing a link to the Globe at Night webapp in social media, posting on message boards where the members would be interested in making observations, and of course making one or more observations yourself! The webapp is available in 28 different languages, so if English is not the first language of your community, be sure to share the relevant app.

The most important days to target this year will be the weekends of March 1-3 and March 29-31. It would therefore be most helpful to spread the word within your networks on March 1 and March 29. Observations are possible throughout the periods February 26-March 7, and March 27-April 5.

I hope that together, we can get a big bump in the data in March, 2019! Thank you for your help in spreading the word!