Search Publications
How much oxygen is too much? Constraining Saturn's ring atmosphere
Goldreich, Peter; Farmer, Alison J.
The discovery of a molecular oxygen atmosphere around Saturn's rings has important implications for the electrodynamics of the ring system. Its existence was inferred from the Cassini in situ detection of molecular oxygen ions above the rings during Saturn Orbit Insertion in 2004. Molecular oxygen is difficult to observe remotely, and theoretical …
Ultraviolet spectroscopy of Comet 9P/Tempel 1 with Alice/Rosetta during the Deep Impact encounter
Parker, Joel Wm.; Bertaux, Jean-Loup; Stern, S. Alan +5 more
We report on spectroscopic observations of periodic Comet 9P/Tempel 1 by the Alice ultraviolet spectrograph on the Rosetta spacecraft in conjunction with NASA's Deep Impact mission. Our objectives were to measure an increase in atomic and molecular emissions produced by the excavation of volatile sub-surface material. We unambiguously detected ato…
Secular light curve of Comet 28P/Neujmin 1 and of spacecraft target Comets 1P/Halley, 9P/Tempel 1, 19P/Borrelly, 21P/Giacobinni Zinner, 26P/Grigg Skjellerup, 67P/Churyumov Gerasimenko, and 81P/Wild 2
Ferrín, Ignacio
We present the secular light curves of eight comets listed in the title. Two plots per comet are needed to study these objects: a reduced magnitude (to Δ=1 AU = geocentric distance) vs time, and a reduced magnitude vs LogR (R=heliocentric distance). A total of over 16 new parameters, are measured from both plots, and give an unprecedented amount o…
Ice-rich terrain in Gusev Crater, Mars?
Gregg, Tracy K. P.; Briner, Jason P.; Paris, Kristen N.
The morphology of materials on the floor of Gusev Crater (14° S, 175° W), Mars, imply a history of volcanism and subsequent removal of an ice-rich deposit. Fluid lava flows observed in the western portion of Gusev Crater paradoxically terminate in a steep, thick ( <60 m) flow front adjacent to hummocky terrain. The hummocky terrain is morpholog…
Properties of the dust cloud caused by the Deep Impact experiment
Jorda, L.; Lara, L. M.; Lamy, P. +7 more
We present an analysis of the observations of the Deep Impact event performed by the OSIRIS narrow angle camera aboard the Rosetta spacecraft over two weeks, in an effort to characterize the cometary dust grains ejected from the nucleus of Comet 9P/Tempel 1. We adopt a Monte Carlo approach to generate calibrated synthetic images, and a linear comb…
Ultraviolet spectroscopy of Comet 9P/Tempel 1 with Alice/Rosetta during the Deep Impact encounter
Parker, Joel Wm.; Bertaux, Jean-Loup; Stern, S. Alan +5 more
We report on spectroscopic observations of periodic Comet 9P/Tempel 1 by the Alice ultraviolet spectrograph on the Rosetta spacecraft in conjunction with NASA's Deep Impact mission. Our objectives were to measure an increase in atomic and molecular emissions produced by the excavation of volatile sub-surface material. We unambiguously detected ato…
SWAN observations of 9P/Tempel 1 around the Deep Impact event
Bertaux, Jean-Loup; Combi, Michael R.; Mäkinen, J. Teemu T. +2 more
The SWAN instrument observed the coma of Comet 9P/Tempel 1 at Lyman alpha around the Deep Impact event. From these observations, a water production rate profile for 3 weeks after the impact was derived. The comet could not be identified in images taken before the impact because of the relatively low production rates. The most important feature of …
Photometric analysis of 1 Ceres and surface mapping from HST observations
Parker, Joel Wm.; Stern, S. Alan; Russell, Christopher T. +5 more
The highest resolution (pixel scale 30 km) images of Ceres to date have been acquired by the Advanced Camera for Surveys onboard Hubble Space Telescope, through three wide band filters, centered at 535, 335, and 223 nm, covering more than one rotation of Ceres. The lightcurve at 535 nm agrees with earlier observations at V-band [Tedesco, E.F., Tay…
Subvisible CO 2 ice clouds detected in the mesosphere of Mars
Montmessin, Franck; Bertaux, Jean-Loup; Perrier, Séverine +8 more
The formation of CO 2 ice clouds in the upper atmosphere of Mars has been suggested in the past on the basis of a few temperature profiles exhibiting portions colder than CO 2 frost point. However, the corresponding clouds were never observed. In this paper, we discuss the detection of the highest clouds ever observed on Mars…
Europa's atmosphere, gas tori, and magnetospheric implications
Smyth, William H.; Marconi, Max L.
A two-dimensional kinetic model calculation for the water group species (H 2O, H 2, O 2, OH, O, H) in Europa's atmosphere is undertaken to determine its basic compositional structure, gas escape rates, and velocity distribution information to initialize neutral cloud model calculations for the most important gas to…