James Webb Telescope Discovers Super-Earth With Atmosphere

“You can see Janssen as Earth, but without the crust,” says Van Bochem. “It’s so warm that the planet’s diurnal surface has likely melted.” Janssen is 25 times as close to its star as Mercury is to the Sun. Due to this small distance, the same side always faces the star, just as the Moon does to the Earth, giving it a permanent day-and-night aspect.

Atmosphere discovered by James Webb

Thanks to the planet’s extremely high temperature, it can be detected by the infrared instruments of the James Webb Telescope, which not only take very beautiful images. The infrared light received comes from the hotter day side, where the temperature without an atmosphere should be about 2,200 degrees Celsius.

But measurements show that the temperature is “only” 1,540 degrees Celsius. The heat is likely to be transferred to the cooler night side, indicating the presence of an atmosphere. “Without an atmosphere, it would be very difficult for that heat energy to move,” says van Bochem.

Dutch organizations

The composition of the atmosphere has also been estimated, which will consist partly of carbon monoxide and carbon dioxide. According to Van Buchem, more research is needed to better map the atmosphere; in the future, other telescopes will be directed towards Janssen, which can measure other wavelengths.

The discoveries at Janssen are due in part to the James Webb Telescope’s new, highly sensitive infrared instruments: NIRCam and MIRI. Dutch organizations played an important role in the development of MIRI. The equipment was installed during the construction of the James Webb Telescope.

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