Galactic Tick Day | |
---|---|
Observed by | international |
Type | Educational |
2023 date | 10 September |
2025 date | 5 June |
Galactic Tick Day is an awareness and education day that celebrates the movement of the Solar System around the Milky Way galaxy.[1][2][3][4]
The day occurs at a regular interval of 1.7361 years (or 633.7 days),[5] which is called a galactic tick. The interval is derived from one centi-arcsecond of a galactic year, which is the Solar System's roughly 225-million-year trip around the Galactic Center.[6] One galactic tick is only about 0.00000077 percent (1/[360 × 60 × 60 × 100]) of a full galactic year.[7]
The Galactic Tick Day was retroactively calculated to begin on the day Hans Lippershey filed the patent for the telescope on 2 October 1608.[8] The first observance of the holiday was on 29 September 2016, the 235th Galactic Tick Day.[9] Below is a list of further observances:
GTD number | Date | Ref |
---|---|---|
1st | 2 October 1608 | [10] |
235th | 29 September 2016 | [10] |
236th | 26 June 2018 | [10] |
237th | 21 March 2020 | [10] |
238th | 15 December 2021 | [10] |
239th | 10 September 2023 | [10] |
240th | 5 June 2025 | [10] |
241st | 1 March 2027 | [10] |
242nd | 24 November 2028 | [10] |
243rd | 20 August 2030 | [10] |