NASA’s James Webb Space Telescope has successfully created a global temperature map of the hot gas-giant exoplanet WASP-43 b, situated some 280 light-years away. Utilizing the Mid-Infrared Instrument (MIRI), the team captured the planet’s emitted mid-infrared light, which ranges from 5 to 12 microns, to infer its temperature. The relationship between mid-infrared light and heat is straightforward—the warmer the object, the greater the infrared radiation it emits.
Though directly observing the planet is challenging due to its proximity to its dazzling host star, astronomers employed a method that involves recording the combined brightness of the star and planet, and then calculating the planet’s own luminosity by subtracting the star’s contribution. This approach is facilitated when the planet passes behind the star.
The comprehensive observations made by Webb over a full 19.5-hour orbital period provided insight into the different temperatures across WASP-43 b. This exoplanet is tidally locked, meaning the same side always faces its star, akin to how the Moon always presents the same face to Earth. As a result, Webb could monitor the varying sides of WASP-43 b as it orbited.
The researchers found that WASP-43 b exhibits a considerable temperature dichotomy: roughly 2,280°F (1,250°C) on its dayside and about 1,115°F (600°C) on its nightside. The findings additionally imply the presence of dense, high-altitude clouds on the nightside, which likely obstruct thermal radiation from escaping the planet’s atmosphere, leading to cooler observed temperatures than what would exist if the clouds were absent.
FAQs about NASA’s Weather Mapping on WASP-43 b
Q: How far away is WASP-43 b?
A: WASP-43 b is located approximately 280 light-years from Earth.
Q: How did NASA’s Webb create the temperature map?
A: NASA’s Webb Telescope measured the mid-infrared light from WASP-43 b using MIRI and subtracted the star’s own brightness to isolate the planet’s luminosity.
Q: Why does WASP-43 b have such different temperatures on its dayside and nightside?
A: The planet is tidally locked, meaning one side is constantly facing the star and receives more heat, while the other faces away and is cooler. High-altitude clouds on the nightside may also contribute to the cooler temperatures observed there.
Q: Can we see WASP-43 b directly?
A: No, direct observation of WASP-43 b is impeded by the bright light of its nearby star, but its brightness can be calculated via indirect methods.
Conclusion
Thanks to the James Webb Space Telescope’s revolutionary capabilities, astronomers have been able to peer into the atmospheric conditions of an exoplanet with unprecedented detail. The mapping of weather patterns on WASP-43 b marks a significant leap in our ability to study distant worlds, furthering our understanding of the universe and the diverse celestial bodies within it. The impressive temperature differences on the planet highlight the extreme conditions that can exist on exoplanets and emphasize the importance of continued exploration and analysis in this fascinating field of astronomy.