James Webb Space Telescope Feed Post

NASA's Webb Investigates Eternal Sunrises, Sunsets on Distant World (Artist Concept)

WASP-39 b is a tidally locked planet: One side is in eternal day, the other in eternal night. By observing the day/night boundary, Webb has confirmed — with extraordinary precision — the differences in temperature and cloud cover between the two sides. Unlike what we may expect on Earth, scientists found the evening side of the day/night boundary of WASP-39 b to be hundreds of degrees hotter than the morning side, and the morning side to likely be cloudier. What’s behind the temperature difference? The team suspects that the morning side of WASP-39 b is getting slammed with cool winds from the nightside, while the evening side is being hit by winds heated on the dayside. Learn more: science.nasa.gov/missions/webb/nasas-webb-investigates-et... Artist Concept Image Credit: NASA, ESA, CSA, Ralf Crawford (STScI) Image description: Illustration of a planet, zoomed in on the planet’s morning side/evening side boundary. The planet encompasses takes up the full image. At the bottom left, the image is dark, depicting the evening side covering the planet in a dark shadow. In the right side of the image, the planet has a fuzzy orange-pink atmosphere with hints of latitudinal wispy cloud bands. The right upper corner is bright, where the star (not illustrated) shines. Image & Description by NASA