The finding has been made thanks to the observation of stars located with respect to the Venus Express , at that time, right on the edge of the Venusian atmosphere. The SPICAV instrument on board the spacecraft analyzed the light from these stars, trying to identify the characteristic trace of gases present in the atmosphere. Ozone was detected because it absorbs part of the ultraviolet light coming from the star.
The ozone molecule contains three oxygen atoms. According to models, ozone on Venus is formed when sunlight breaks down carbon dioxide molecules, releasing oxygen atoms in the process. These atoms are carried by the winds in the atmosphere to the night face of the planet; There they combine in pairs, forming molecules of two atoms and also, sometimes, in trios. In addition to helping to understand the chemistry of Venus, the find could be useful in the search for life on other planets.
Ozone has so far only been detected in the atmospheres of Earth, Mars, and now Venus as well . On Earth it is of great importance because it absorbs much of the sun's ultraviolet radiation, which is harmful to life.
