Search Publications
SOHO SWAN Lyα Models Supporting LRO LAMP: 2008–2023
Pryor, Wayne R.; Gladstone, G. Randall; Quémerais, Eric +5 more
The Lunar Reconnaissance Orbiter Lyman-Alpha Mapping Project (LAMP) has been mapping the Moon since its launch in 2009. Faint ultraviolet illumination of the lunar dark side includes light from stars and from hydrogen Lyα emissions, mostly attributed to sunlight scattered by hydrogen atoms near the Sun with a smaller contribution from the whole Ga…
Stellar Occultations in the Era of Data Mining and Modern Regression Models: Using Gaussian Processes to Analyze Light Curves and Improve Predictions
Person, Michael J.; Levine, Stephen E.; Krabbe, Alfred +3 more
Gaussian process (GP) regression is a nonparametric Bayesian approach that has been used successfully in various astronomical domains, especially in time-domain astronomy. The most common applications are the smoothing of data for interpolation and the detection of periodicities. The ability to create unbiased data-driven models without a predefin…
Characterization of the Dust and Sodium Tails of Comet C/2020 F3 (NEOWISE) from Parker Solar Probe and Amateur Observations
Coates, Andrew J.; Afghan, Qasim; Jones, Geraint H. +2 more
Comet C/2020 F3 (NEOWISE) reached perihelion on 2020 July 3 at 0.29 au and exhibited a highly structured dust tail. Using a simplified Finson–Probstein model, structures such as striae, observed in the tail in images obtained by the Parker Solar Probe spacecraft and amateur observers, are characterized in this work and parameterized in terms of du…
Observations of Uranus at High Phase Angle as Seen by New Horizons
Mayorga, L. C.; Singer, Kelsi N.; Stern, S. Alan +14 more
We present flux measurements of Uranus observed at phase angles of 43.°9, 44.°0, and 52.°4 by the Multispectral Visible Imaging Camera on the New Horizons spacecraft during 2023, 2010, and 2019, respectively. New Horizons imaged Uranus at a distance of about 24–70 au (2023) in four color filters, with bandpasses of 400–550 nm, 540–700 nm, 780–975 …
Accretion of Meteoric Organic Matter at the Surface of Mars and Potential Production of Methane by Ultraviolet Radiation
Janches, Diego; Villanueva, Gerónimo L.; Carrillo-Sánchez, Juan Diego +1 more
In this study, a comprehensive model of the meteoric organic cycle on Mars for the current geological period is developed, which characterizes the ablation of exogenous organic matter in the upper atmosphere, the accretion of intact carbon at the surface, and the potential production of methane by UV photolysis from the surface reservoir. The mode…
Dual Sources of S2 Observed in Comet 67P: Insights from Comparing ROSINA Measurements and Laboratory Simulations
Choukroun, Mathieu; Hodyss, Robert; Mahjoub, Ahmed +2 more
Hydrogen sulfide (H2S) is the fifth most abundant molecule observed in the coma of comet 67P/Churyumov–Gerasimenko (67P). Prior to its incorporation into cometary materials, H2S likely underwent ultraviolet (UV) radiation exposure, which is thought to initiate a complex sulfur chemistry. We present an investigation into the U…
3 µm Phase Curves of Main-belt Asteroids from NEOWISE Photometry
Oszkiewicz, Dagmara; Masiero, Joseph; Chanover, Nancy +1 more
The shapes of asteroid phase curves are influenced by the physical properties of asteroid surfaces. The variation of an asteroid's brightness as a function of the solar phase angle can tell us about surface properties such as grain size distribution, roughness, porosity, and composition. Phase curves are traditionally derived from photometric obse…
Characterization of the Ejecta from the NASA/DART Impact on Dimorphos: Observations and Monte Carlo Models
Licandro, Javier; Kolokolova, Ludmilla; Li, Jian-Yang +26 more
The NASA Double Asteroid Redirection Test (DART) spacecraft successfully crashed on Dimorphos, the secondary component of the binary (65803) Didymos system. Following the impact, a large dust cloud was released, and a long-lasting dust tail developed. We have extensively monitored the dust tail from the ground and the Hubble Space Telescope. We pr…
Strong Depletion of 13C in CO Induced by Photolysis of CO2 in the Martian Atmosphere, Calculated by a Photochemical Model
Aoki, Shohei; Yoshida, Nao; Terada, Naoki +7 more
The isotopic signature of atmospheric carbon offers a unique tracer for the history of the Martian atmosphere and the origin of organic matter on Mars. The photolysis of CO2 is known to induce strong isotopic fractionation of the carbon between CO2 and CO. However, its effects on the carbon isotopic compositions in the Martia…
(523599) 2003 RM: The Asteroid that Wanted to be a Comet
Granvik, Mikael; Wainscoat, Richard J.; Weryk, Robert +11 more
We report a statistically significant detection of nongravitational acceleration on the subkilometer near-Earth asteroid (523599) 2003 RM. Due to its orbit, 2003 RM experiences favorable observing apparitions every 5 yr. Thus, since its discovery, 2003 RM has been extensively tracked with ground-based optical facilities in 2003, 2008, 2013, and 20…