Short answers, pulled from the story.
Titan was discovered by the Dutch astronomer Christiaan Huygens on the 25th of March, 1655. Huygens built his own telescopes with the help of his elder brother Constantijn Huygens Jr. and became the first person to identify a moon orbiting Saturn.
Titan's atmosphere is primarily nitrogen, at about 98.6% in the stratosphere, with methane at roughly 4.92% near the surface and hydrogen at around 0.1%. Trace hydrocarbons including ethane, acetylene, and propene are also present, along with carbon dioxide, hydrogen cyanide, argon, and helium.
Titan has lakes and seas of liquid methane and ethane, concentrated near its polar regions. The three largest northern seas, Kraken Mare, Ligeia Mare, and Punga Mare, together cover 691,000 square kilometers. Liquid hydrocarbons were confirmed on the surface in January 2007 by the Cassini mission.
Huygens landed on the 14th of January, 2005, just off the easternmost tip of a bright region called Adiri. It photographed pale hills streaked with dark rivers leading to a dark plain, and after landing captured images of a plain covered in small pebbles of water ice. The site was later named the Hubert Curien Memorial Station.
Scientists consider Titan a prebiotic environment but not a confirmed habitat. Hypothetical methanogenic organisms could theoretically live in Titan's methane lakes, inhaling hydrogen and exhaling methane, but would need to function at around -179 degrees Celsius. Measurements of lower-than-expected hydrogen and acetylene near Titan's surface are consistent with biological consumption but have non-biological explanations considered more probable.
Dragonfly is a large drone powered by a radioisotope thermoelectric generator, developed by the Johns Hopkins Applied Physics Laboratory and scheduled to launch in July 2028. It will fly through Titan's atmosphere as the New Frontiers 4 mission and is planned to arrive in the mid-2030s to study how far prebiotic chemistry has progressed on the moon.