In focus: Titan
Introduction
- Titan is the only moon of Saturn that has a size comparable to that of our own moon.
- It is the second largest moon in our solar system after Ganymede of Jupiter.
Features
- Thick atmosphere
- Titan is the only moon that has a thick atmosphere. (about 200 km)
- The atmosphere is composed of 95% nitrogen, traces of methane, ethane, acetylene, ethylene and propane.
- Composition
- As a result of high atmospheric pressure and low temperature (-178 degree Celsius), hydrocarbons such as methane, ethane exist as liquid on Titan.
- As a result it is the only place other than earth that has standing liquid on its surface.
Cassini Mission and its findings
- Launched in 1997, reached Saturn in 2004
- Joint effort of NASA, European Space Agency and the Italian Space Agency.
- Final flyby in 2017.
Objectives
- Study of composition, structure, weather, origin and evolution of Saturn
- Structure and composition of Saturn’s rings
- Study of Titan and other small icy satellites of Saturn
Key discoveries
- Cassini spacecraft was the first to observe Titan to have rain, rivers, lakes and seas made of hydrocarbons.
- First to observe nitrogen-rich atmosphere.
- Current discovery
- Titan’s northern hemisphere has lakes 300 ft deep made of methane.
- The lakes are on top of landforms similar to mesas or butte on earth (flatlands) in Karst topography.
- Further there are small shallow lakes (called phantom lakes) seasonal in nature that appear in winter and evaporate in summer.
Section : Science & Tech
