Venus crosses the Sun above Tahiti

Publication supplied tools for calculating motions of planets and comets, though later work refined them.

NASA's UTC catalog dates the transit to 6 June; some observers described it as 5 June in their local time.

Teams at widely separated sites recorded the transit to help estimate the Earth–Sun distance.

Astronomers sought to compare the instants when Venus crossed the solar limb across different locations.

The indistinct contact of Venus with the solar edge complicated the measurements made at this transit.

European expedition members observed from an island with its own navigational and celestial knowledge traditions.

Cook and Green's drawings helped document the event and the difficulty of timing its edge.

Observations from Tahiti were compared with observations elsewhere to estimate the scale of the solar system.

He recorded a small object in Gemini, at first thinking it might be a comet.

Later observations showed that Herschel's object was a planet beyond Saturn.