Both Earth and Titan have nitrogen-dominated atmospheres -- over 95 percent nitrogen in Titan's case. However, unlike Earth, Titan has very little oxygen; the rest of the atmosphere is mostly methane and trace amounts of other gases, including ethane. And at the frigid temperatures found at Saturn's great distance from the sun, the methane and ethane can exist on the surface in liquid form.
For this reason, scientists had long speculated about the possible existence of hydrocarbon lakes and seas on Titan, and data from the NASA/ESA Cassini-Huygens mission does not disappoint. Since arriving in the Saturn system in 2004, the Cassini spacecraft has revealed that more than 620,000 square miles (1.6 million square kilometers) of Titan's surface -- almost two percent of the total -- are covered in liquid.
There are three large seas, all located close to the moon's north pole, surrounded by numerous of smaller lakes in the northern hemisphere. Just one large lake has been found in the southern hemisphere.
The exact composition of these liquid reservoirs remained elusive until 2014, when the Cassini radar instrument was first used to show that Ligeia Mare, the second largest sea on Titan and similar in size to Lake Huron and Lake Michigan combined, is methane-rich. A new study published in the Journal of Geophysical Research: Planets, which used the radar instrument in a different mode, independently confirms this result.
How to make oxygen on Titan There are five known ways oxygen can be created:
The most common natural method is photo-synthesis, in which plants use sunlight convert carbon dioxide in the air into oxygen.
2) Oxygen starved Bacteria (is the latest new way).
In 2010, a team of scientist found that bacteria could consume methane and were producing oxygen by a previously unknown biochemical process. In the presence of nitrates there was no consumption of methane, but when nitrites were added, the bacteria consumed methane and released nitrogen. The microbiologists proposed the bacteria produce nitrogen and oxygen from two molecules of nitric oxide, which in turn is produced from the nitrites. The oxygen would then be used to burn the methane for energy, with the nitrogen released as a waste product. The enzyme or enzymes used in the process are so far unknown.
x3) The most common commercial method for producing oxygen is the separation of air using either a cryogenic distillation process or a vacuum swing adsorption process. Nitrogen and argon are also produced by separating them from air.
4) Oxygen can also be produced as the result of a chemical reaction in which oxygen is freed from a chemical compound and becomes a gas. This method is used to generate limited quantities of oxygen for life support on submarines, aircraft, and spacecraft.
5) Hydrogen and oxygen can be generated by passing an electric current through water and collecting the two gases as they bubble off. Hydrogen forms at the negative terminal and oxygen at the positive terminal. This method is called electrolysis and produces very pure hydrogen and oxygen. It uses a large amount of electrical energy, however, and is not economical for large-volume production.
Note: Oxygen is reactive and will form oxides with all other elements except the noble gases: helium, neon, argon and krypton.
A molecule of methane consists of 4 hydrogen atoms and one carbon atom. To burn, you need two O2 molecules. The burning looks like: CH4 + 2 02 -> CO2 * 2H2O The process gives off energy (that means the molecules will have high velocity and heat up the surroundings, perhaps triggering other methane and oxygen molecules to combine.)
Thus, methane can be used to create CO2 & Water. Water can then be drunk or used to make Oxygen.