Description of the comet of 1531, 16th century.
© Science Museum / Science & Society Picture Library
Handwritten page of text describing the appearance of the bright comet that appeared in the heaven in 1531. Detached from a 16th century commonplace book, the description is an early account of the passage of Halley's comet across the skies. Unlike most comets, which have very long period orbits, this one returns at regular interval of about 76 years. The English astronomer, Edmond Halley (1656-1742) discovered this periodicity and predicted it would return in 1758. The comet duly returned long after Halley's death and is named in his honour. The last apparition of the comet in our skies occurred in 1986-7 during which an armada of spacecrafts were dispatched from the Earth to study it in detail.