John Herschel Glenn Jr. was born on July 18, 1921, in Cambridge, Ohio, the son of John Herschel Glenn Sr. , who worked for a plumbing firm, and Clara Teresa née Sproat, a teacher. His parents had married shortly before John Sr. , a member of the American Expeditionary Force, left for the Western Front during World War I. The family moved to New Concord, Ohio, soon after his birth, and his father started his own business, the Glenn Plumbing Company. Glenn Jr. was only a toddler when he met Anna Margaret (Annie) Castor, whom he would later marry. The two would not be able to recall a time when they did not know each other. He first flew in an airplane with his father when he was eight years old. He became fascinated by flight, and built model airplanes from balsa wood kits. Along with his adopted sister Jean, he attended New Concord Elementary School. He washed cars and sold rhubarb to earn money to buy a bicycle, after which he took a job delivering The Columbus Dispatch newspaper. He was a member of the Ohio Rangers, an organization similar to the Cub Scouts. His boyhood home in New Concord has been restored as a historic house museum and education center.
But there is an important difference. On our own planet, lakes and seas are flowing with water, while Titan's lakes and seas are filled primarily with methane and ethane, that slosh around within these liquid reservoirs. In this never-before-seen cycle, the hydrocarbon molecules evaporate and condense into clouds that send an exotic "rain of terror" back down to this strange moon-world's carbon-slashed surface. The precise chemical composition of these very alien lakes and seas remained unknown until 2014, when Cassini's radar instrument detected Ligeia Mare, now known to be Titan's second-largest hydrocarbon-filled lake. Ligeia Mare is brimming with an abundance of sloshing methane, and this enormous liquid reservoir is approximately the same size as two of Earth's Great Lakes combined--Lake Michigan and Lake Huron. Many planetary scientists think that the seabed of Ligeia Mare may be blanketed with a thick layer of sludge that is composed of organic-rich compounds. Jupiter, along with its beautiful ringed sister planet, Saturn, are the gas-giant duo of our Sun's family of eight major planets. The other two giant planets--that dwell in our Solar System's outer limits--are Uranus and Neptune. Uranus and Neptune are classified as ice giants, because they carry within them larger cores than Jupiter and Saturn, as well as thinner gaseous envelopes. Jupiter and Saturn may (or may not) contain small, hidden cores, that are heavily veiled by extremely massive, dense gaseous envelopes.