In a study published in Nature Astronomy, researchers from the University of Cambridge have cast doubt on the possibility that Venus ever harboured oceans or supported life. The findings, derived from an analysis of Venus's atmospheric chemistry, suggest that the planet may have been devoid of liquid water throughout its history. Despite its similarities to Earth in terms of size and proximity to the Sun, Venus appears to have always been an uninhabitable environment.
Chemical Analysis Reveals Dry History
The investigation focused on the atmospheric composition of Venus, examining how key gases like water vapour, carbon dioxide, and carbonyl sulfide are destroyed and replenished. Tereza Constantinou, a PhD student at Cambridge's Institute of Astronomy and the study's lead author, explained that the planet's interior and exterior interact chemically, which provides insights into its past. It was discovered that Venus's volcanic gases are composed of less than 6 percent steam, pointing to a dry planetary interior incapable of sustaining water-based oceans.
Theories on Venus's Evolution
Two prevailing theories have sought to explain Venus's evolution. One posits that the planet initially hosted liquid water but lost it due to a runaway greenhouse effect. The other suggests that Venus was "born hot," with conditions unsuitable for water from the outset. The team's findings align with the latter, indicating a fundamentally dry history.
Implications for Exoplanet Research
Constantinou, speaking to Live Science, noted that these conclusions could influence the search for habitable exoplanets. Planets with conditions similar to Venus may no longer be considered prime candidates for supporting life. She stated that if Venus never had oceans, the likelihood of similar planets hosting habitable conditions diminishes.
NASA's upcoming DAVINCI mission, scheduled for launch in 2029, may provide further clarity, as per reports. Its probe, expected to descend through Venus's atmosphere, could offer crucial insights into the planet's surface conditions, though it is not designed to survive the descent.
The findings highlight Venus's unique evolution and reinforce the need for focused exploration of exoplanets with greater potential for habitability.
