Tycho Brahe, born at Knudstrup in Scania, Denmark, has been raised by his uncle, Jorgen Brahe, who had sent the thirteen-year-old in 1559 to Copenhagen to study law.

The observation of a solar eclipse in 1560 had turned Tycho’s interest to observational astronomy and, contrary to his uncle's intentions, he has studied the subject independently, using Ptolemy's Almagest.

Tycho Brahe is sixteen years old in 1563 when he observes the conjunction of Jupiter and Saturn, an event that clearly demonstrates to him the inaccuracy of the existing records of planetary positions.