???? Fall of comets and polar auroras: Jupiter's atmosphere abused

2023-07-19 06:00:10

The fall of Comet Shoemaker-Levy 9 at 44°S into Jupiter’s atmosphere in July 1994 produced new species in its stratosphere, i.e. above the cloud layer usually photographed in the visible . These species, such as carbon monoxide (Carbon is a chemical element of the family of crystallogens, symbol C,…) (CO) and cyanide (Cyanides are the compounds of the anion CN-, formed of a carbon atom bonded by…) hydrogen (Hydrogen is a chemical element with symbol H and atomic number 1.) (HCN) are very stable species over time in the atmosphere of Jupiter (The atmosphere of Jupiter is the most important of the atmospheres of the planets…), because they have a very long chemical lifespan.
Jupiter photographed by amateur astronomer Christopher Go on March 22, 2017, that is to say the day of the observations (Observation is the action of attentive monitoring of phenomena, without the will to…) ALMA. The bright areas indicate the emission of HCN, concentrated at the limb of the planet (A planet is a celestial body orbiting around the Sun or another star of…). An HCN hole is observed in the northern and southern auroral regions and at nearby latitudes. A small production region of very high altitude (Altitude is the vertical elevation of a place or an object with respect to a level…) is located inside the southern aurora.
© T. Cavalié and C. Go.

More than 20 years after the impacts of the comet, these species should therefore have contaminated all the latitudes and longitudes of the planet. The maps of the emission of these species with the ALMA (Atacama Large Millimeter/submillimeter Array) millimeter interferometer show, however, that while CO follows this trend, the same is not true for HCN. In the auroral zones and at neighboring latitudes, a research team (Scientific research designates in the first place all the actions undertaken with a view to…) observed a hole in HCN in the average (The average is a statistical measurement characterizing the elements of a set of…) stratosphere (The stratosphere is the second layer of the Earth’s atmosphere, located above the…), a sign that the species (In the life sciences, the species (from the Latin species, “type”…) is destroyed in these regions and at these altitudes.

Scientists believe that the organic aerosols that are produced in the auroras are responsible for this hole, by adsorbing HCN on their surface. Even more unexpectedly, the data (In information technology (IT), a datum is a basic description, often…) reveal an HCN production zone at very high altitudes and inside the Auroras of Jupiter. The energy (In the common sense, energy designates everything that makes it possible to carry out work, manufacture…) deposited by the magnetosphere (The magnetosphere is the region surrounding a celestial object in which the phenomena… ) in the auroras is a strong candidate to explain this highly localized production.