Search Publications
Constraining the thermal properties of planetary surfaces using machine learning: Application to airless bodies
Furfaro, Roberto; Cambioni, Saverio; Delbo, Marco +2 more
We present a new method for the determination of the surface properties of airless bodies from measurements of the emitted infrared flux. Our approach uses machine learning techniques to train, validate, and test a neural network representation of the thermophysical behavior of the atmosphereless body given shape model, illumination and observatio…
The Martian daytime convective boundary layer: Results from radio occultation measurements and a mesoscale model
Pätzold, M.; Hinson, D. P.; Häusler, B. +4 more
We investigate the behavior of the Martian daytime convective boundary layer (CBL) through a combination of data analysis and modeling. This study relies on two subsets of Mars Express radio occultation (RO) measurements that sounded the atmosphere in northern spring of successive Mars years. Only the first year of observations has been examined p…
Araneiform terrain formation in Angustus Labyrinthus, Mars
Jaumann, R.; Hao, J.; Michael, G. G. +1 more
The south polar area of Mars exhibits an abundance of distinctive and exotic landforms, most of which occur within the region covered by the seasonal CO2 cap. Araneiform terrain (also referred to as terrain covered by "spiders") is one of these unusual geomorphic features, resulting from CO2 sublimation driven seasonal erosio…
Fine-scale structure in cometary dust tails I: Analysis of striae in Comet C/2006 P1 (McNaught) through temporal mapping
Morgan, Huw; Jones, Geraint H.; Battams, Karl +5 more
Striated features, or striae, form in cometary dust tails due to an as-yet unconstrained process or processes. For the first time we directly display the formation of striae, at C/2006 P1 McNaught, using data from the SOHO LASCO C3 coronagraph. The nature of this formation suggests both fragmentation and shadowing effects are important in the form…
A stellar occultation by Vanth, a satellite of (90482) Orcus
Bosh, A. S.; Lister, T. A.; Schindler, K. +5 more
A stellar occultation by the large trans-Neptunian object (90482) Orcus was predicted to occur on 2017 March 07. Observations were made at five sites in North and South America: the 0.6-m Astronomical Telescope of the University of Stuttgart (ATUS) at Sierra Remote Observatories, California; Las Cumbres Observatory's 1-m telescope at McDonald Obse…
Interior properties of the inner Saturnian moons from space astrometry data
Lainey, V.; Noyelles, B.; Rambaux, N. +3 more
During the thirteen years in orbit around Saturn before its final plunge, the Cassini spacecraft provided more than ten thousand astrometric measurements. Such large amounts of accurate data enable the search for extremely faint signals in the orbitalmotion of the saturnian moons. Among these, the detection of the dynamical feedback of the rotatio…
Studies of irregular satellites: I. Lightcurves and rotation periods of 25 Saturnian moons from Cassini observations
Mottola, Stefano; Denk, Tilmann
Disk-integrated time-resolved photometric observations have been performed for 25 irregular moons of Saturn with the ISS camera of the Cassini spacecraft in a wide range of solar phase angles. From the derived lightcurves, synodic rotation periods were determined, ranging from 5.5 h to 76 h; the fastest observed spin rate is much slower than the d…
An equatorial thermal wind equation: Applications to Jupiter
Wong, Michael H.; Tollefson, Joshua; Marcus, Philip S. +1 more
To relate the vertical wind shear to horizontal temperature gradients at and near the equator, we derive an "Equatorial Thermal Wind Equation" (EQTWE) using a minimum set of assumptions that are easily satisfied for the atmospheres of all the giant planets and Earth. Similar to the textbook Thermal Wind Equation (TWE), the EQTWE requires a small R…
Ultraviolet observation of Enceladus' plume in transit across Saturn, compared to Europa
Hansen, C. J.; Hendrix, A. R.; Esposito, L. W.
Saturn's moon Enceladus is known to have a water vapor plume erupting from fissures across its south polar region. The plume was detectable in an observation of Enceladus transiting Saturn by Cassini's Ultraviolet Imaging Spectrograph (UVIS), but only at 1216 Å (Lyman alpha). Jupiter's moon Europa also may have multiple water vapor plumes, detecte…
First measurements of Jupiter's zonal winds with visible imaging spectroscopy
Sato, Bun'ei; Rivet, Jean-Pierre; Guillot, Tristan +12 more
We present the first measurements of Jupiter's wind profile ever obtained with Doppler velocity measurements in the visible. Hitherto, knowledge about atmospheric dynamics has been obtained with cloud-tracking techniques, which consist of tracking visible features from images taken at different dates. However, cloud tracking indicates the motion o…