International observers time Venus

The first edition laid out laws of motion and universal gravitation.

The new work used the same gravitational principle to explain motion on Earth and in the heavens.

Newton presented mathematical arguments for orbital motion and other celestial phenomena.

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.

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.

Cook and Green recorded the transit from Tahiti during an international observing campaign.

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.