Christiaan Huygens (April 14, 1629 – July 8, 1695) was a prominent Dutch mathematician and scientist.
He is known particularly as an astronomer, physicist, probabilist and horologist.
Huygens was a leading scientist of his time. His work included early telescopic studies of the rings of Saturn and the discovery of its moon Titan, the invention of the pendulum clock and other investigations in timekeeping. He published major studies of mechanics and optics, and a pioneer work on games of chance.
Titan (or Saturn VI) is the largest moon of Saturn. It is the only natural satellite known to have a dense atmosphere, and the only object other than Earth where clear evidence of stable bodies of surface liquid has been found.
Titan is the sixth ellipsoidal moon from Saturn. Frequently described as a planet-like moon, Titan’s diameter is 50% larger than Earth’s natural satellite, the Moon, and it is 80% more massive. It is the second-largest moon in the Solar System, after Jupiter’s moon Ganymede, and is larger by volume than the smallest planet, Mercury, although only 40% as massive. Discovered in 1655 by the Dutch astronomer Christiaan Huygens, Titan was the first known moon of Saturn, and the fifth known satellite of another planet.