Search Publications
Water production rates from SOHO/SWAN observations of comets C/2020 S3 (Erasmus), C/2021 A1 (Leonard) and C/2021 O3 (PanSTARRS)
Bertaux, J. -L.; Combi, M. R.; Quémerais, E. +2 more
In 2021 and 2022 the hydrogen comae of three long period comets, C/2020 S3 (Erasmus), C/2021 A1 (Leonard) and C/2021 O3 (PanSTARRS) were observed with the Solar Wind ANisotropies (SWAN) all-sky hydrogen Lyman-alpha camera on the SOlar and Heliosphere Observer (SOHO) satellite. SWAN obtains nearly daily full-sky images of the hydrogen Lyman-α distr…
Observations of a dust tail gap in comet C/2014 Q1 (PanSTARRS)
Afghan, Qasim; Jones, Geraint H.; Price, Oliver +1 more
Cometary dust tails display a wide array of structures, most believed to be caused by a variable dust production, size distributions, fragmentation processes, and interactions with the solar wind, e.g. Price et al. (2019). However, not all these structures are fully understood. Here we report the discovery of a curious new dust tail feature, first…
Energy deposition in Saturn's equatorial upper atmosphere
Hu, X.; Galand, M.; Yelle, R. V. +6 more
We construct Saturn equatorial neutral temperature and density profiles of H, H2, He, and CH4, between 10-12 and 1 bar using measurements from Cassini's Ion Neutral Mass Spectrometer (INMS) taken during the spacecraft's final plunge into Saturn's atmosphere on 15 September 2017, combined with previous deeper atmosp…
Cometary ions detected by the Cassini spacecraft 6.5 au downstream of Comet 153P/Ikeya-Zhang
Jones, G. H.; McComas, D. J.; Smith, E. J. +5 more
During March-April 2002, while between the orbits of Jupiter and Saturn, the Cassini spacecraft detected a significant enhancement in pickup proton flux. The most likely explanation for this enhancement was the addition of protons to the solar wind by the ionization of neutral hydrogen in the corona of comet 153P/Ikeya-Zhang. This comet passed rel…
Carbon photochemical escape rates from the modern Mars atmosphere
Yelle, Roger V.; Lillis, Robert J.; Lo, Daniel Y. +1 more
We provide a comprehensive update of photochemical escape rates of atomic carbon from the present-day Martian atmosphere using a one-dimensional photochemical model and a Monte Carlo escape model. The photochemical model incorporates new results relevant to carbon photochemistry at Mars, including new cross sections for photodissociation of CO
Simultaneous sublimation activity of primitive asteroids including (24) Themis and (449) Hamburga: Spectral signs of an exosphere and the solar activity impact
Petrova, Elena V.; Busarev, Vladimir V.; Irsmambetova, Tatiana R. +2 more
We describe and analyze simultaneous sublimation activity of the main-belt primitive asteroids during their perihelion passages, which was detected by spectral methods. This phenomenon was observed for the first time in September 2012 for asteroids (145) Adeona, (704) Interamnia, (779) Nina, and Mars-crosser (1474) Beira (Busarev et al., 2015, 201…
Comet 21P/Giacobini-Zinner: Water production activity over 20 years with SOHO/SWAN
Bertaux, J. -L.; Combi, M. R.; Quémerais, E. +3 more
In 1985 Comet 21P/Giacobini-Zinner was the first comet visited by a spacecraft, the International Cometary Explorer (ICE) satellite, several months before the armada of Halley spacecraft had their encounters in 1986. ICE was originally the ISEE-3 satellite, designed for magnetospheric measurements near the Earth, and was diverted via a lunar gravi…
Water production rates from SOHO/SWAN observations of six comets: 2017-2020
Bertaux, J. -L.; Combi, M. R.; Shou, Y. +4 more
The Solar Wind ANisotropies (SWAN) all-sky hydrogen Lyman-alpha camera on the SOlar and Heliosphere Observer (SOHO) satellite makes daily images of the entire sky to monitor the three-dimensional distribution of solar wind and solar radiation via its imprint on the stream of interstellar hydrogen that flows through the solar system. In the process…
Carbon photochemistry at Mars: Updates with recent data
Yelle, Roger V.; Lillis, Robert J.; Lo, Daniel Y.
We provide a comprehensive characterization of the photochemistry behind atomic carbon in the Mars atmosphere. Using a one-dimensional photochemical model, with an extensive reaction list incorporating new high-resolution photodissociation cross-sections (Heays et al., 2017) and the recently experimentally confirmed CO2 + hν →C +O2…
A survey of water production in 61 comets from SOHO/SWAN observations of hydrogen Lyman-alpha: Twenty-one years 1996-2016
Bertaux, J. -L.; Combi, M. R.; Quémerais, E. +2 more
The Solar Wind Anisotropies (SWAN) instrument on the SOlar and Heliospheric Observatory (SOHO) satellite has observed 44 long period and new Oort cloud comets and 36 apparitions of 17 short period comets since its launch in December 1995. Water production rates have been determined from the over 3700 images producing a consistent set of activity v…