Titan
Of Saturn's satellites, Titan is the largest; it is also the sole moon known to carry a substantial atmosphere.[3]
History
Titan was first sighted by Christiaan Huygens, on March 25, 1655.[3]
Findings
Nitrogen makes up most of Titan's atmosphere, with methane as a smaller component.[3] Titan's surface has lakes and seas containing methane and ethane in liquid form.[3] JPL reports Titan's mean radius as 2,574.76 kilometres.[1] Mapped named terrain on Titan includes seas, lakes, and mountains.[2]