In 1639, the transit of Venus (its passage across the Sun's disc) was first observed by astronomer Jeremiah Horrocks.

CNN: Sunday,

James Cook, a year into his circumnavigation of the world, observed the transit of Venus over the Sun's disc, the main purpose of his voyage.

CNN: Tuesday,

Those viewing outside the favoured zone were treated to a partial eclipse, in which the Moon just took a bite out of the side of the Sun's disc.

BBC: Skywatchers see 'ring of fire'

They concluded that the black drop results from blurring of the image (whether from Earth's atmosphere, or inevitable imperfections of the telescope) combined with the way that the disc of the sun fades in brightness towards its rim.

ECONOMIST: Transits of Venus

As the Moon's disc began to leave the Sun, it was light again, and birds, which had flown to their nests only minutes earlier, came chirping out again.

BBC: Under the Moon's shadow