|Observed by||Astronomers and astronomy enthusiasts|
|Observances||astronomy-related events and competitions|
|Date||Saturday between mid-April and mid-May on or just before the first quarter moon|
Astronomy Day is an annual event intended to provide a means of interaction between the general public and various astronomy enthusiasts, groups and professionals.
This event was started in 1973 by Doug Berger, the president of the Astronomical Association of Northern California. His intent was to set up various telescopes in busy urban locations so that passersby could enjoys views of the heavens. Since then the event has expanded and is now sponsored by a number of organizations associated with astronomy.
Astronomy Day also forms part of Astronomy Week, which begins on the preceding Monday.
Originally, Astronomy Day occurred on a Saturday between mid-April and mid-May, and was scheduled so as to occur at or close to the first quarter Moon. In 2007, an autumn rendition of Astronomy Day was added. It was scheduled to occur on a Saturday between mid-September and mid-October so as to be on or close to the first quarter Moon.
The lunar influence on the schedule means that the events happen on a different date each year, rather than set calendar dates. The table below shows the dates for Astronomy Day:
|2005||Spring||April 16th||April 16th|
|2006||Spring||May 6th||May 5th|
|2007||Spring||April 21st||April 24th|
|2008||Spring||May 10th||May 12th|
|2009||Spring||May 2nd||May 1st|
|2010||Spring||April 24th||April 21st|
|2010||Fall||October 16th||October 14th|
|2011||Spring||May 7th||May 10th|
|2011||Fall||October 1st||October 3rd|
|2012||Spring||April 28th||April 30th|
|2012||Fall||October 20th||October 21st|
|2013||Spring||April 20th||April 18th|
|2013||Fall||October 13th||October 11th|
|2014||Spring||May 10th||May 7th|
|2014||Fall||October 4th||October 1st|
- Night sky
- Sky brightness
- Amateur astronomy
- Apparent magnitude
- Sky & Telescope (S&T)
- Bortle Dark-Sky Scale
- Light pollution
- Dark-sky movement
- Dark-sky preserve
- International Dark-Sky Association (IDA)