Article
Astronomy & Astrophysics
Kathleen Mandt, Adrienn Luspay-Kuti, Olivier Mousis, Sarah E. Anderson
Summary: Scientists have discovered that the volatiles on the surfaces of Pluto and Triton are deficient in carbon and have similar abundances of nitrogen and water compared to other objects. These findings are important for understanding the origins of Pluto and Triton, as well as the formation locations and times of other Kuiper Belt objects.
ASTROPHYSICAL JOURNAL
(2023)
Article
Astronomy & Astrophysics
Darrell F. Strobel
Summary: The paper aims to investigate whether the H-2 density measurements reported by Cassini were overestimated by a factor of 2.2, and the potential impact of this overestimation on the atmospheres of Titan and Saturn.
Article
Astronomy & Astrophysics
Nicholas A. Lombardo, Juan M. Lora
Summary: Titan's atmosphere shows variations in composition as it goes through different seasons. Winter stratosphere above 100 km has been found to have higher amounts of short-lived molecules. Seasonal changes in stratospheric dynamics on Titan also lead to a transient detached haze layer above 400 km. These seasonal variations affect the radiative heating rates in both shortwave and longwave regions. Based on simulations using the Titan Atmospheric Model (TAM), this study examines the impact of a new dataset derived from Cassini observations on aerosol opacity and trace gas abundance. The results show that including seasonally varying radiative species (SVRS) decreases the temperature of polar stratopause in autumn and winter by up to 10 K, and increases the seasonality in zonal winds.
Article
Geochemistry & Geophysics
J. Mouzay, I. Couturier-Tamburelli, N. Pietri, T. Chiavassa
Summary: Laboratory experiments were conducted to study the photochemical evolution induced by long-UV irradiation of benzene ices in Titan's atmosphere. The formation of volatile photo-products and residue dominated by nu CH IR features from UV photolysis of benzene ices were observed, providing insights into the composition of Titan's stratospheric haze layer. Additionally, the characterization of benzene-containing aerosol analogs induced by long-UV will contribute to Titan's surface organics layer and future Dragonfly space mission.
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
(2021)
Article
Astronomy & Astrophysics
Scot C. R. Rafkin, Juan M. Lora, Alejandro Soto, J. Michael Battalio
Summary: The deep convective cloud-environment feedback loop is crucial for understanding Titan's global methane, energy, and momentum cycles. This study uses cloud resolving modeling to quantify the effects of deep convective methane storms on their environment and improve parameterizations in global models.
Article
Engineering, Aerospace
Jinee Gogoi, Kalyan Bhuyan, Som Kumar Sharma, Bitap Raj Kalita, Rajesh Vaishnav
Summary: This study examines major and minor SSW events in the Northern Hemisphere over the past four decades from a statistical perspective. It finds a correlation between the timing of early minor SSW events and final events, with the lowest correlation observed during the 2001-2010 decade. The study also reveals different behaviors of stratospheric parameters depending on the number of SSW events in a winter. Additionally, ionospheric parameters show variation from event to event and exhibit significant latitudinal variations.
ADVANCES IN SPACE RESEARCH
(2023)
Article
Astronomy & Astrophysics
Danica Adams, Yangcheng Luo, Yuk L. Yung
Summary: Titan has a similar atmosphere to that of an early Earth-like world, with the potential for relevant prebiotic chemistry. Exo-Titan worlds at close-in orbits also have the conditions suitable for habitability. The study finds that increased incident radiation leads to faster reaction rates. Higher temperatures and a larger H-2 abundance promote cycling and chemical reactions.
FRONTIERS IN ASTRONOMY AND SPACE SCIENCES
(2022)
Article
Astronomy & Astrophysics
Roger Yelle, T. T. Koskinen, M. Y. Palmer
Summary: The study analyzed data from Titan's occultation of three stars in Orion's belt, revealing information on atmospheric composition, thermal structure, density distributions of different molecules, and aerosol extinction. Significant variations in latitude for certain molecules, aerosols, and temperature were found, providing insights into global circulation patterns. The inferred mole fractions of various molecules were consistent with photochemical model predictions, but with some overestimations and underestimations at different pressure levels.
Article
Astronomy & Astrophysics
J. Michael Battalio, Juan M. Lora, Scot Rafkin, Alejandro Soto
Summary: The influence of methane on the circulation of Titan is investigated using a simplified moist convection parameterization scheme. The results show that the reference relative humidity has a significant impact on convective instability and precipitation, while the relaxation timescale of convection has minor effects. The behavior of convection varies with the relative humidity, with infrequent and intense events at low relative humidity and near-continuous precipitation at high relative humidity during summer. Intermediate relative humidity values result in frequent events of moderate intensity.
Article
Astronomy & Astrophysics
M. Dobrijevic, J. C. Loison, V Hue, T. Cavalie
Summary: Observational data of Titan's atmosphere composition, gathered by missions like Cassini, provide insights into the dynamics of various chemical species' altitude profiles. Developing a 2D photochemical model for Titan that considers complex chemical schemes and latitudinal variations has shown to significantly impact the accuracy of density profiles for neutrals and ions. Therefore, the use of radiative transfer models in a 2D geometry is recommended for interpreting observational data about Titan's atmosphere.
Article
Astronomy & Astrophysics
J. Mouzay, K. Henry, I Couturier-Tamburelli, G. Danger, N. Pietri, T. Chiavassa
Summary: A massive noxious stratospheric cloud has been detected on Titan's south pole since 2015, with an experimental simulation showing the presence of nitriles formed through photo-processing. These results are crucial for the upcoming Dragonfly mission on Titan, shedding light on the potential organic compounds present in the stratospheric cloud.
Article
Geosciences, Multidisciplinary
F. Comola, J. F. Kok, J. M. Lora, K. Cohanim, X. Yu, C. He, P. McGuiggan, S. M. Horst, F. Turney
Summary: Titan, Saturn's largest moon, has huge linear dunes and an active dust cycle. Similar to Earth, these aeolian processes are caused by wind moving surface grains. However, it is still unclear how saltation can occur on Titan with its weak winds and potentially cohesive grains. This study suggests that saltation may occur on Titan through granular splash instead of aerodynamic lifting, and the prevailing circulation on Titan can generate significant yet intermittent saltation.
GEOPHYSICAL RESEARCH LETTERS
(2022)
Article
Engineering, Aerospace
Teyen Widdicombe, R. A. Borrelli
Summary: A pressure vessel was used to simulate the atmosphere of Titan and measure neutron attenuation. The results showed that the atmosphere and surface material have minimal impact on neutron measurements. This study confirms the accuracy of neutron modeling and concludes that neutrons from MMRTG are unlikely to affect Dragonfly's measurements on Titan's surface.
Article
Astronomy & Astrophysics
Darci Snowden, Alexandre Higgins
Summary: The study shows that Titan's induced magnetosphere is effective in shielding the atmosphere from thermal proton precipitation but only partially shields it from thermal oxygen precipitation. The energy deposited by thermal magnetospheric oxygen is lower than solar EUV input but similar to energy deposited by high energy neutral atoms and magnetospheric electrons.
Article
Astronomy & Astrophysics
Erich Karkoschka
Summary: An analysis of three new image cubes of Titan by the Space Telescope Imaging Spectrograph reveals that Titan's seasonal variation is close to harmonic and not influenced by variations due to Saturn's orbital eccentricity. The reversal consists of two components, with small temporary deviations observed. These new observations provide an improved seasonal model that will help in future global circulation models of Titan.
