Search Publications
Heterogeneous chemistry in the atmosphere of Mars
Montmessin, Franck; Bertaux, Jean-Loup; Perrier, Séverine +6 more
Hydrogen radicals are produced in the martian atmosphere by the photolysis of water vapour and subsequently initiate catalytic cycles that recycle carbon dioxide from its photolysis product carbon monoxide. These processes provide a qualitative explanation for the stability of the atmosphere of Mars, which contains 95 per cent carbon dioxide. Bala…
An equatorial oscillation in Saturn's middle atmosphere
Strobel, D. F.; Flasar, F. M.; Bézard, B. +3 more
The middle atmospheres of planets are driven by a combination of radiative heating and cooling, mean meridional motions, and vertically propagating waves (which originate in the deep troposphere). It is very difficult to model these effects and, therefore, observations are essential to advancing our understanding of atmospheres. The equatorial str…
Depth of a strong jovian jet from a planetary-scale disturbance driven by storms
Hueso, R.; Sánchez-Lavega, A.; Rojas, J. F. +22 more
The atmospheres of the gas giant planets (Jupiter and Saturn) contain jets that dominate the circulation at visible levels. The power source for these jets (solar radiation, internal heat, or both) and their vertical structure below the upper cloud are major open questions in the atmospheric circulation and meteorology of giant planets. Several ob…
Discovery of the progenitor of the type Ia supernova 2007on
Nelemans, Gijs; Voss, Rasmus
Type Ia supernovae are exploding stars that are used to measure the accelerated expansion of the Universe and are responsible for most of the iron ever produced. Although there is general agreement that the exploding star is a white dwarf in a binary system, the exact configuration and trigger of the explosion is unclear, which could hamper their …
Semi-annual oscillations in Saturn's low-latitude stratospheric temperatures
Tokunaga, Alan T.; Baines, Kevin H.; Hora, Joseph L. +25 more
Observations of oscillations of temperature and wind in planetary atmospheres provide a means of generalizing models for atmospheric dynamics in a diverse set of planets in the Solar System and elsewhere. An equatorial oscillation similar to one in the Earth's atmosphere has been discovered in Jupiter. Here we report the existence of similar oscil…
An 84-µG magnetic field in a galaxy at redshift z = 0.692
Jorgenson, Regina A.; Heiles, Carl; Wolfe, Arthur M. +2 more
The magnetic field pervading our Galaxy is a crucial constituent of the interstellar medium: it mediates the dynamics of interstellar clouds, the energy density of cosmic rays, and the formation of stars. The field associated with ionized interstellar gas has been determined through observations of pulsars in our Galaxy. Radio-frequency measuremen…
Atmospheric structure and dynamics as the cause of ultraviolet markings in the clouds of Venus
Drossart, Pierre; Piccioni, Giuseppe; Markiewicz, Wojciech J. +4 more
When seen in ultraviolet light, Venus has contrast features that arise from the non-uniform distribution of unknown absorbers within the sulphuric acid clouds and seem to trace dynamical activity in the middle atmosphere. It has long been unclear whether the global pattern arises from differences in cloud top altitude (which was earlier estimated …
The determination of the structure of Saturn's F ring by nearby moonlets
Charnoz, Sébastien; Murray, Carl D.; Beurle, Kevin +3 more
Saturn's narrow F ring exhibits several unusual features that vary on timescales of hours to years. These include transient clumps, a central core surrounded by a multistranded structure and a regular series of longitudinal channels associated with Prometheus, one of the ring's two `shepherding' satellites. Several smaller moonlets and clumps have…
Flares from a candidate Galactic magnetar suggest a missing link to dim isolated neutron stars
Hanlon, L.; McBreen, B.; Bremer, M. +39 more
Magnetars are young neutron stars with very strong magnetic fields of the order of 1014-1015G. They are detected in our Galaxy either as soft γ-ray repeaters or anomalous X-ray pulsars. Soft γ-ray repeaters are a rare type of γ-ray transient sources that are occasionally detected as bursters in the high-energy sky. No optical…
Jovian-like aurorae on Saturn
Bunce, Emma J.; Melin, Henrik; Miller, Steve +5 more
Planetary aurorae are formed by energetic charged particles streaming along the planet's magnetic field lines into the upper atmosphere from the surrounding space environment. Earth's main auroral oval is formed through interactions with the solar wind, whereas that at Jupiter is formed through interactions with plasma from the moon Io inside its …