SMALL PRINT:OZONE LINGERS in the atmosphere of Venus, according to new findings from the European Space Agency's Venus Express spacecraft.
So far only Earth and Mars had been known to have the gas in their atmospheres, where it can shield against UV rays. But signs of ozone also turned up as Venus Express watched starlight from its vantage point near our other neighbouring planet, Venus.
“[the spacecraft’s] SPICAV instrument analysed the starlight, looking for the characteristic fingerprints of gases in the atmosphere as they absorbed light at specific wavelengths,” explains an article on ESA’s website.
“The ozone was detectable because it absorbed some of the ultraviolet from the starlight.”
Computer models indicate that the ozone on Venus is formed when sunlight breaks up carbon dioxide molecules to release oxygen atoms, which then combine to form ozone, according to the piece. The layer sits around 100km above Venus and is less dense than the ozone layer around Earth.
But the news about stratospheric ozone back on Earth isn’t quite as jovial. NASA’s website reports on research it led that found “an unprecedented depletion of Earth’s protective ozone layer above the Arctic last winter and spring, caused by an unusually prolonged period of extremely low temperatures in the stratosphere.”
An Antarctic ‘ozone hole’ emerged in the 1980s and depletion results in a hole over the Antarctic each year, note the authors, who published their findings in Nature this month.
To date observed ozone loss over the Arctic has been more limited, but not this year, it seems.
“Here we demonstrate that chemical ozone destruction over the Arctic in early 2011 was, for the first time in the observational record, comparable to that in the Antarctic ozone hole,” they write. “For the first time, sufficient loss occurred to reasonably be described as an Arctic ozone hole.”