Saturn’s moon, Titan, has been considered a “unique world in the solar system” since 1908 when, the Spanish astronomer, José Comas y Solá, discovered that it had an atmosphere, something non-existent on other moons. One of Saturn’s 60 moons, Titan is the only moon in the solar system large enough to support an atmosphere.
Titan is the only moon in the solar system with a substantial atmosphere, and the origin of its nitrogen-rich air is a mystery. A new theory is that the atmosphere was created 3.9 billion years ago in a period known as the late heavy bombardment, when armadas of comets zipped through the solar system.
“Huge amounts of cometary bodies would have collided with outer icy satellites, including Titan,” says Yasuhito Sekine of the University of Tokyo, Japan.