According to a new study, the unusual behaviour of sulphur in Venus' atmosphere cannot be explained by an 'aerial' form of extra-terrestrial life. Researchers from the University of Cambridge used a combination of biochemistry and atmospheric chemistry to test the 'life in the clouds' hypothesis, which astronomers have speculated about for decades, and found that life cannot explain the composition of the Venusian atmosphere. Any life form in sufficient abundance is expected to leave chemical fingerprints on a planet's atmosphere as it consumes food and expels waste. However, the Cambridge researchers found no evidence of these fingerprints on Venus. Even if Venus is devoid of life, the researchers say their results, reported in the journal Nature Communications, could be useful for studying the atmospheres of similar planets throughout the galaxy, and the eventual detection of life outside our Solar System. "Life is pretty good at weird chemistry, so we've been studying whether there's a way to make life a potential explanation for what we see." The researchers used a combination of atmospheric and biochemical models to study the chemical reactions that are expected to occur, given the known sources of chemical energy in Venus's atmosphere.