Dutch physicist, mathematician, astronomer and inventor Christiaan Huygens was born on 14 April 1692 in The Hague
Inspired by Galileo’s discovery of the four largest moons of Jupiter – Io, Europa, Ganymede and Callisto in 1610 he started building telescopes around 1650 with the help of his brother.
On 25 March 1655, he discovered Saturn’s largest moon, Titan, which he called ‘Luna Saturni’ (Saturn’s Moon). Later John Herschel named it Titan.
With a diameter of 5,149.46 kilometres, it is larger than the planet Mercury and the second-largest natural satellite in the Solar System after Jupiter’s Ganymede.
50% larger than Earth’s moon, it is the only moon known to have a dense atmosphere and, after the Earth, the only known body in space to show evidence of stable bodies of liquid on its surface