Search Publications
A 1D Model of Radial Ion Motion Interrupted by Ion-Neutral Interactions in a Cometary Coma
Vigren, E.; Eriksson, A. I.
Because ion-neutral reaction cross sections are energy dependent, the distance from a cometary nucleus within which ions remain collisionally coupled to the neutrals is dictated not only by the comet’s activity level but also by the electromagnetic fields in the coma. Here we present a 1D model simulating the outward radial motion of water group i…
Plasma Environment around Comet 67P/Churyumov-Gerasimenko at Perihelion: Model Comparison with Rosetta Data
Altwegg, K.; Goetz, C.; Goldstein, R. +6 more
The plasma environment near comet 67P/Churyumov-Gerasimenko (67P/CG) is dynamically affected by various factors, including the incident solar wind and outgassing from the nucleus. The Rosetta spacecraft MAGnetometer (MAG) instrument observations near perihelion showed crossing events into a magnetic field-free region at about 170 km from the nucle…
Imaging Observations of the Hydrogen Coma of Comet 67P/Churyumov-Gerasimenko in 2015 September by the PROCYON/LAICA
Combi, Michael R.; Shinnaka, Yoshiharu; Fougere, Nicolas +8 more
The water production rate of a comet is one of the fundamental parameters necessary to understand cometary activity when a comet approaches the Sun within 2.5 au, because water is the most abundant icy material in the cometary nucleus. Wide-field imaging observations of the hydrogen Lyα emission in comet 67P/Churyumov-Gerasimenko were performed by…
Beyond 3 au from the Sun: The Hypervolatiles CH4, C2H6, and CO in the Distant Comet C/2006 W3 (Christensen)
Villanueva, Geronimo L.; Mumma, Michael J.; DiSanti, Michael A. +5 more
Comet C/2006 W3 (Christensen) remained outside a heliocentric distance (R h) of 3.1 au throughout its apparition, but it presented an exceptional opportunity to directly sense a suite of molecules released from its nucleus. The Cryogenic Infrared Echelle Spectrograph at ESO-VLT detected infrared emissions from the three “hypervolatiles”…
New Horizons Upper Limits on O2 in Pluto’s Present Day Atmosphere
Stern, S. A.; Olkin, C. B.; Weaver, H. A. +7 more
The surprising discovery by the Rosetta spacecraft of molecular oxygen (O2) in the coma of comet 67P/Churyumov-Gerasimenko challenged our understanding of the inventory of this volatile species on and inside bodies from the Kuiper Belt. That discovery motivated our search for oxygen in the atmosphere of Kuiper Belt planet Pluto, because…