April 10, 2025: A Tiny Biosphere Implying Fermentation In The Presumed Subsurface Ocean Of Titan ?
A new research work entitled "The Viability of Glycine Fermentation in Titan's Subsurface Ocean", published in The Planetary Science Journal by the American Astronomical Society on April 7, 2025 and proposed by a team of planetologists involving Antonin Affholder and Peter Higgins reveals the potential mechanisms that are likely to allow the development of a lifeform based on fermentation processes in the presumed subsurface ocean of Titan. Organics can form in the atmosphere and on the surface of the giant moon of Saturn. Impact events related to meteorites or comets can engender the development of pools beneath the surface and can engender migrations of materials from the soil to the interior of that world. Interactions between the hydrocarbons or the organics of the upper layer and the potential pockets of liquid water may engender more complex molecules such as amino acids that can migrate toward the presumed subsurface ocean rich in liquid water. The researchers of the study tried to evaluate the likelihood of a biosphere related to the exchanges of organics or carbon-made molecules between the core, the hypothetical subsurface ocean and the upper layer of the Opaque Moon.
The potential biosphere of the presumed subsurface ocean of Saturn's largest moon may be based on fermentation processes. The planetologists suggest that glycine fermentation is a potential metabolism occurring beneath the icy crust of that world. Glycine appears to be the simplest amino acid we know and amino acids are the building blocks of life on Earth. In the hypothetical subsurface ocean of Titan likely devoid of any oxygen, anaerobic fermentation processes can be considered because those processes don't rely on oxygen. The team of Antonin Affholder resorted to bioenergetic modeling in order to evaluate the potential presence and the potential extent of that type of biosphere. It turns out that the conditions beneath the external crust are likely to allow the presence of glycine fermentation and it also appears that those types of processes are closely related to the temperature factor. Any biosphere based on glycine fermentation would have to face a slow or limited delivery of glycine via impact melt pools. In the presumed subsurface ocean of water found beneath the external crust of Titan, any potential biosphere may be extremely poor in terms of mass due to the relatively limited amount of carbon-based molecules coming from the surface or the core.
February 18, 2025: Evaluations Of The Tidal Dissipation Rate Of Titan Bring Clues To The Dynamics Of Its Interior And To A Turbulent Past
A new research work entitled "Titan's spin state as a constraint on tidal dissipation", proposed by Brynna G. Downey and Francis Nimmo and published in Science Advances in Volume 11 and in Issue 6 on February 5, 2025 reveals an evaluation of the tidal dissipation rate of the giant moon of Saturn Titan and brings clues related to the dynamics and the nature of its interior and related to its history. Some researchers suggest the presence of a subsurface ocean rich in liquid water beneath the external crust of the Opaque Moon. The evaluations of the team of researchers suggest a relatively significant level of energy inside Titan and a relatively turbulent past. The orbit of that moon is not perfectly circular. Titan has an elliptical orbit around Saturn so that the level of tidal forces undergone by the giant moon changes over time during the long Titanian year. When Titan is closer to Saturn, it undergoes higher levels of tidal forces. When Titan is farther from Saturn, it undergoes lower levels of tidal forces related to the gravitational forces of the Gas Giant Saturn. The variations in the level of tidal forces imply an internal activity and the presence of a potential subsurface ocean beneath the external crust.
The physical and orbital characteristics of Titan clearly suggest that the moon is an active world. The value of the eccentricity of the Opaque Moon is 0.0288. Therefore, the orbit of Titan corresponds to an ellipse. The orbital period of that world is 15.945 days. In other words, it takes almost 16 days for Titan to perform a revolution around Saturn. The inclination of the orbit of Titan relative to the plane of Saturn's equator represents 0.34854 degrees. The axial tilt of Titan relative to the Sun represents 27 degrees. Over a geologic timescale, the characteristics of the orbit of Titan should evolve toward the characteristics of a circular orbit perfectly aligned with the plane of the equator of Saturn. The current characteristics of the orbit of the Orange Moon suggest that Titan has experienced significant events in its relatively recent geologic past. A strong meteorite impact can have influenced its orbital characteristics or a change in its orbital environment may have destabilized its orbit resulting in the current orbital configuration. Titan evolves in a relatively crowded environment where numerous moons can be found. Many interactions between planetary bodies can occur over a geologic timescale.
January 29, 2025: Experimental Heating Of Complex Organics Demonstrates That Internal Activity Plays A Role In The Stability Of The Atmosphere Of Titan
A new study entitled "Experimental heating of complex organic matter at Titan's interior conditions supports contributions to atmospheric N2 and CH4", published in Geochimica et Cosmochimica Acta in the volume 390 of February 1, 2025 and proposed by a team of researchers involving Doctor Kelly Miller of the Southwest Research Institute reveals the potential role of the internal chemistry of Titan in the stability of its atmosphere. The largest moon of the Gas Giant Saturn is clearly a unique world in the Solar System due to its remarkable atmosphere that is deep and thick and that may resemble the atmosphere of the Early Earth. The atmosphere of Titan is in fact dominated by molecular nitrogen like the atmosphere of the Blue Planet. Nitrogen represents about 95 percent of the composition of the atmosphere of the giant moon which represents a higher fraction than that of nitrogen in our own atmosphere (around 78 percent). Oxygen that is widespread in our own atmosphere, representing about 21 percent of the composition, is absent or almost absent in the atmosphere of Titan. The atmosphere of that exotic world unveils a relatively high concentration of methane (around 5 percent of the composition at sea level).
How can we explain that Titan contains a significant atmosphere whereas most of the other moons in the Solar System are devoid of any atmosphere ? The largest moon in the Solar System that is to say Ganymede is devoid of any significant atmosphere for instance. Yet, that moon is relatively big and it evolves in a relatively cold environment around the Gas Giant Jupiter. A world like Mercury is also devoid of any significant atmosphere. Yet, Mercury is bigger than our moon, The Moon, but it evolves in a very warm environment around the Sun so that volatiles can more easily escape from the gravity of the planet. The presence of any atmosphere is in fact closely related to the factor of gravity and to the factor of environmental temperature. In principle, there must be the right combination of gravity and environmental temperature for the presence and the stability of any atmosphere. Worlds like Triton and Pluto contain a thin atmosphere. That configuration is probably related to the right combination of gravity and environmental temperature. Their gravity is particularly weak compared to that of the Earth but they evolve in an extremely harsh environment where the ambient temperature is much lower than that of the Earth.