Using observations of Venus performed with an instrument on ESA's Venus Express scientists have detected, for the first time, a tenuous layer of ozone in this planet's atmosphere. Located at an altitude of about 100 km, the layer is up to a thousand times less dense than the one found, at a lower altitude, in the Earth's stratosphere, but both are dominated by very similar chemical reactions.
The discovery poses new challenges to the characterisation of planetary atmospheres, especially in the quest for biomarkers on extrasolar planets.
Ozone (O3) is one of the most notable molecules populating the atmosphere of the Earth. Present there only in moderate quantities with respect to other, more abundant molecules-nitrogen, oxygen and carbon dioxide, among others-ozone plays an essential role in preserving life on Earth.
