Editing 1769 in science (section)

==Astronomy==
* March 4 –  [[French people|French]] astronomer [[Charles Messier]] first records the [[Orion Nebula]] (''[[Messier objects|Messier]] 42'').
* June 3 – [[Transit of Venus]] is observed from many places in order to obtain data for measuring the distance from the [[Earth]] to the [[Sun]]. Those taking part include
** [[Jean-Baptiste Chappe d'Auteroche]] at [[San José del Cabo]], [[Baja California]]
** [[James Cook]] and [[Charles Green (astronomer)|Charles Green]] on [[Tahiti]]
** [[Jeremiah Dixon]] and [[William Bayly (astronomer)|William Bayly]] in northern [[Norway]], Dixon at [[Hammerfest (town)|Hammerfest]] and Bayly at [[North Cape, Norway|North Cape]]
** [[Maximilian Hell]] and [[János Sajnovics]] in [[Vardø (town)|Vardø]], Norway
** [[Guillaume Le Gentil]] in [[Pondicherry (city)|Pondicherry]], [[India]]: Le Gentil had hoped to go to [[Manila]] in the [[Philippines]] but was turned away by the local Spanish colonial governor. The weather in Pondicherry is cloudy that day. Le Gentil had also missed the 1761 transit through bad luck.
** [[Alexandre Guy Pingré]] in [[Haiti]]
** [[William Wales (astronomer)|William Wales]] and [[Joseph Dymond]] at [[Prince of Wales Fort]] on [[Hudson Bay]]
** [[Anders Johan Lexell]] and [[Christian Mayer (astronomer)|Christian Mayer]] in [[Saint Petersburg]]; with other members of [[Russian Academy of Sciences]] at eight other locations in the [[Russian Empire]]
** Members of the [[American Philosophical Society]] at three locations
The transit is followed five hours later by a total [[solar eclipse]] visible from Britain.
* November 9 – Transit of [[Mercury (planet)|Mercury]]. James Cook observes this from Mercury Bay in [[New Zealand]].
* [[Pluto|Pluto's]] 8th complete orbit around the Sun from its present-day position