Venus's slow rotation and fast clouds explained

Astronomers have identified a planet where a single day lasts longer than its entire year, while its upper atmosphere completes a full rotation in just four days. The planet, designated WASP-43b, is a hot Jupiter located about 280 light-years from Earth. It orbits its star so closely that a year there is only 19.5 hours long, yet its rotation period is 23.5 hours, meaning the planet's day is longer than its year. This unusual phenomenon is caused by tidal locking, similar to how the Moon always shows the same face to Earth.

The discovery was made using data from NASA's Spitzer Space Telescope, which observed the planet over several orbits. The researchers, led by a team from the University of Exeter, measured the planet's rotation by tracking the motion of its hot spot, a region of extreme temperature on the dayside. They found that the planet rotates more slowly than previously thought, which affects our understanding of its atmospheric dynamics.

This finding matters because it challenges existing models of how exoplanets behave. The slow rotation means that the planet's atmosphere may be more complex than expected, with strong winds that could explain why the clouds move so fast. The study was published in the journal Nature Astronomy. The next step for researchers is to use the James Webb Space Telescope to observe WASP-43b in more detail, which could reveal more about its atmospheric composition and weather patterns.