Facts about Titan's Methane Cycle
- 08
Titan's surface evaporation rates peak during southern summer when solar heating increases methane sublimation from hydrocarbon dunes covering approximately 17 percent of the moon's equatorial regions.
- 07
Around 10 kilometers below Titan's surface, a cryovolcanic water-ammonia ocean may exchange material with the methane cycle through subsurface reservoirs and possible cryovolcanic vents.
- 06
Liquid ethane and propane, not pure methane, comprise most of Titan's polar lakes discovered by Cassini's radar between 2004 and 2017.
- 05
Atmospheric methane on Titan condenses into organic compounds called tholins when ultraviolet radiation from the Sun breaks down the methane molecules in the upper atmosphere.
- 04
Seasonal variations cause Titan's methane precipitation to shift between hemispheres during its 29-year orbital cycle around Saturn.
- 03
Methane clouds in Titan's upper atmosphere form at altitudes of 40 to 60 kilometers, creating a complex meteorological system distinct from lower-altitude precipitation patterns.
- 02
Titan's methane evaporates from its surface and rises through the atmosphere, creating a complete cycle analogous to Earth's water cycle over approximately 10 million years.
- 01
Cassini measurements revealed Titan's methane cycle involves rain and liquid methane lakes concentrated near polar regions at temperatures around minus 179 degrees Celsius.