"While just 40% the diameter of the Earth, Titan has an atmosphere 1.5 times as dense as the Earth's, even with a lower gravity," said Dr. Kelly Miller of SwRI, lead author of a study published in Geochimica et Cosmochimica Acta. "Walking on the surface of Titan would feel a bit like scuba diving."
Titan's atmosphere, comprised of approximately 95% nitrogen and 5% methane, has intrigued scientists since its discovery in 1944. The atmosphere's origins and persistence are a mystery, as methane's chemical breakdown caused by sunlight would deplete the gas within 30 million years, potentially freezing the atmosphere onto Titan's surface.
"The presence of methane is critical to the existence of Titan's atmosphere," Miller explained. "Scientists believe there must be an internal source replenishing the methane, or the atmosphere would have an extremely short geological lifetime."
In 2019, Miller authored a theoretical paper in the Astrophysical Journal, suggesting that Titan's atmosphere is replenished by gases released from its interior. The hypothesis posits that complex organic materials in Titan's rocky interior undergo heating, releasing nitrogen and carbon gases, including methane. These gases then escape to the surface, forming the moon's dense atmosphere.
Recent laboratory experiments have confirmed key aspects of this model. Researchers replicated Titan's interior conditions by heating organic materials to temperatures between 250 and 500 degrees Celsius under pressures as high as 10 kilobars. These experiments successfully generated carbon gases, including carbon dioxide and methane, in quantities sufficient to sustain Titan's atmospheric composition.
The findings build on data from NASA's Cassini-Huygens mission, which studied the Saturn system extensively between 2004 and 2017. Future exploration will continue with NASA's Dragonfly mission, set to launch in 2028. The Dragonfly spacecraft, equipped with a quadcopter, will investigate Titan's surface and assess its potential habitability, including its subsurface liquid ocean. Miller is collaborating with an international team to examine the habitability of this ocean further.
Research Report:Experimental heating of complex organic matter at Titan's interior conditions supports contributions to atmospheric N2 and CH4
Related Links
Planetary Science at SwRI
Explore The Ring World of Saturn and her moons
Jupiter and its Moons
The million outer planets of a star called Sol
News Flash at Mercury
| Subscribe Free To Our Daily Newsletters |
| Subscribe Free To Our Daily Newsletters |
