Scientists have identified enormous concentric rings encircling Venus’s dayside atmosphere from a single 30-minute observation made in 2010, publishing their findings in The Planetary Science Journal after more than a decade of analysis.
The rings were detected by a polarimeter, an experimental instrument mounted on the William Herschel Telescope in the Canary Islands. The device captures linearly polarized light, which forms when sunlight scatters through gases and dust. The instrument revealed rings surrounding much of the planet’s dayside, as if Venus were resonating like a bell.
Shortly after the observation, the polarimeter was dismantled and its parts reused for other projects, leaving researchers with a single unrepeatable dataset. The team, led by atmospheric physicist Gourav Mahapatra, spent years trying to attribute the signal to instrument error, examining possible causes such as detector digitization faults and light blurring. After ruling out technical failures, Mahapatra’s team concluded the most rigorous scientific course was to publish the data, acknowledge its limitations, and invite the broader community to attempt confirmation.
To explain the pattern, the researchers ran computer simulations and proposed a hypothesis involving atmospheric gravity waves — disturbances that travel through dense atmospheres by compressing and expanding gas, similar to ripples from a stone dropped in a pond. The models showed that density variations of between 5 and 10 percent in Venus’s upper atmosphere were sufficient to alter the polarization of sunlight and produce the observed rings.
If confirmed, the discovery could offer a new tool for studying Venus’s atmospheric superrotation, a phenomenon in which winds circle the entire planet in just four Earth days, even though Venus itself takes 243 days to complete one rotation on its axis.
The original polarimeter no longer exists, but the researchers said current instruments at observatories around the world could search for the same polarized light signatures in Venus’s twilight sky.
