Transit of Venus of 1769
- When
- 1769
- Where
- Transit of Venus visible from Earth; King's Observatory (later known as Kew Observatory), near Richmond Lodge
- Episodes
- 2
On 3 June 1769, Venus crossed the face of the Sun in a transit visible from Earth. King George III observed the event from the King's Observatory near Richmond Lodge, an observatory completed that year specifically so the King and Astronomer Royal Stephen Demainbray could view the transit. No solar eclipse accompanied the transit.
Episodes
- Transit of Venus of 3 June 1769
Venus passed between the Sun and Earth on 3 June 1769, visible as a small black disk crossing the Sun.
- King George III observes the transit at the King's Observatory
King George III observed the 3 June 1769 transit from the King's Observatory near Richmond Lodge, completed that year for this purpose.
Background and detail
Background. A transit of Venus occurs when Venus passes directly between the Sun and the Earth, appearing as a small black circle moving across the solar disk. Transits occur in pairs eight years apart, separated by gaps of over a century, and sequences usually repeat every 243 years. The 1769 transit fell within a June pair.
The King's Observatory. King George III had the King's Observatory built near his summer residence at Richmond Lodge, where the royal family resided between 1764 and 1771. The observatory was completed in 1769, in time for the King's observation of the transit of Venus on 3 June of that year.
Scientific Significance. For the 1769 transit, scientists travelled to places all over the world. Transits offered the first opportunities to accurately calculate the distance from Earth to Venus, from which the astronomical unit and distances of other Solar System bodies could be determined. In 1771, Jérôme Lalande used the combined 1761 and 1769 data to calculate the astronomical unit as 153 ± 1 million kilometres.
People involved
- King George III · King of Great Britain; observed the transit from the King's Observatory
- Stephen Demainbray · Astronomer Royal; intended to observe the transit alongside the King
Sources
- Transit of Venus Wikipedia, revision of 2026-09-11
- King's Observatory Wikipedia, revision of 2026-09-21
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