When Sunrise and Sunset Are Eternal: A Glimpse into the Surprising World of Exoplanets

According to the statistics of the Exoplanet Archive at The National Aeronautics and Space Administration (NASA), among the billions of exoplanets, over 5,700 exoplanets in 4,289 planetary systems are confirmed, with 962 systems having more than one planet. “WASP-39b is a giant exoplanet orbiting a remote sun-like star 700 light-years away in the Virgo constellation. As a giant planet, it has a diameter 1.3 times greater than Jupiter and a similar mass to Saturn. Unlike the cooler, smaller gas giant in the solar system, WASP-39b orbits very close to its star – only about one-eighth the distance between the Sun and Mercury, thus completes a circle around its star in just four Earth-days.”

In 2022, a year after it became the first exoplanet to be examined by the James Webb Telescope, the presence of carbon dioxide in WASP 39b was confirmed. “Learning about the atmospheres of other worlds is how we identify those that could potentially support life.” Published in Nature, the latest discovery based on observations of the Webb Telescope reveals a perpetual atmospheric difference in this tidally locked world. “The day side would be constantly exposed to the star’s heat and light, while the night side would be in perpetual darkness and cold.” Contrary to what we’d expect, the evening side of WASP-39b is a scorching 200 degrees Celsius hotter than its morning side. So, what’s causing this extraordinary phenomenon? Astronomers have pinpointed the culprit: WASP 39b’s gas circulation. The extreme temperature difference creates a significant air pressure difference, leading to intense wind speeds. This finding becomes a benchmark for other exoplanets studies.