Astronomers first detect carbon dioxide in the atmosphere of a planet outside the solar system

American scientists have discovered carbon dioxide in the atmosphere of a planet the size of Saturn, which is located at a distance of 700 light-years from us. This is the first clear evidence of the existence of this gas on a planet outside the solar system.

We are talking about the hot gas giant WASP-39b, which revolves around its star in 4 days in an orbit much smaller than that of Mercury. The scientists received their first data on July 10 and began analysis shortly thereafter. But even without additional processing, they recorded a clear spectral dip in CO₂.

Astronomer Jacob Bean from the University of Chicago told Science about this. According to him, this is the first confirmation of carbon dioxide in the atmosphere of another planet: previous signals did not stand up to scrutiny. And the spectral data from the "Webb" leaves no doubt about the detected substance.

Carbon dioxide is important in calculating the metallicity of a planet—that is, the concentrations of elements heavier than helium and hydrogen within it. Judging by the signal, the metallicity of WASP-39b roughly corresponds to Saturn, and the masses of the planets are also similar. It's amazing that these planets have a lot in common, considering how different their orbits are.

Hubble and Spitzer have previously detected water vapor, sodium and potassium in the atmosphere of WASP-39b. Now "James Webb" has added CO₂, as well as another gas, the spectral response at first could not be deciphered. Bean notes that this mystery has been solved, but the results will be publicly announced only after additional verification of the results by experts.

The researchers believe that as the telescope can get closer to less hot planets, in size comparable to Earth, we are in for a lot more surprises - perhaps even gases that indicate the suitability of these planets for life.