Once again, the James Webb Space Telescope (JWST) amazes us, this time by acting as a space weather predictor. Imagine a tool worth a whopping $10 billion, originally made by some smart individuals at NASA. Now, think of a diverse team of astronomers from all over the world eagerly using it to uncover the secrets of space.
In its latest adventure, the JWST is focusing on something extremely fascinating i.e., WASP-43 b, a huge exoplanet far, far away—about 280 light years from us. Picture it like a giant Jupiter, but super hot getting its name ‘hot Jupiter’ for a reason.
This planet’s temperatures could match the sun’s surface, and its winds are wild, blowing faster than 5,000 miles per hour. But here’s the kicker: WASP-43 b has a quirky side. It’s tidally locked, which means one part is always burning under its nearby star while the other stays in never-ending darkness. It’s like a wild rollercoaster of extreme temperatures.
Taylor Bell, researcher from the Bay Area Environmental Research Institute and lead author of a study published on Tuesday (30 April) in Nature Astronomy, said: “With Hubble, we could clearly see that there is water vapour on the dayside. Both Hubble and Spitzer suggested there might be clouds on the nightside.
“But we needed more precise measurements from Webb to really begin mapping the temperature, cloud cover, winds, and more detailed atmospheric composition all the way around the planet.”
WASP-43 b takes 19.5 hours to go around its star, with the JWST measuring tiny changes in brightness of the planet and its neighbours.
To unravel the atmospheric enigmas enveloping WASP-43 b, the JWST employed sophisticated techniques, including precise measurements of luminosity spanning various mid-infrared wavelengths. By integrating these measurements with advanced 3D climate models and data acquired from prior observations, the telescope offered unprecedented insights into the planet’s thermal profile, cloud formations, and atmospheric constituents.
Utilizing its Near-InfraRed Camera (NIRCam), the JWST meticulously monitored WASP-43 b, capturing data at intervals of every 10 seconds over a duration exceeding 24 hours. This continuous surveillance facilitated the calculation of the planet’s thermal profile as different hemispheres rotated into view, unveiling stark differentials in temperature between the sunlit and shadowed regions.
Bell said: “By observing over an entire orbit, we were able to calculate the temperature of different sides of the planet as they rotate into view. From that, we could construct a rough map of temperature across the planet.”
The scalding temperatures observed on the illuminated side, nearing a staggering 1,250 degrees Celsius, coupled with the relentless supersonic winds sweeping across the planetary surface, hindered the formation of methane—a critical indicator of atmospheric stability.
The JWST’s ability to map temperature differences on WASP-43 b highlights how sensitive and reliable its instruments are. The noticeable lack of methane on the planet’s shadowed side hints at swift air movements in the atmosphere, hindering the creation of methane. This significant finding sheds light on the complex weather patterns of exoplanets and emphasizes the crucial role of space telescopes like the JWST in expanding our understanding of the universe.