JWST has spotted chemical reactions in an exoplanet's atmosphere

Alex Wilkins is a writer.

The telescope spotted chemical reactions in the atmosphere of a distant alien world for the first time, raising hopes that it could help identify planets that host life.

When the planet first formed, many of the compounds in Earth's atmosphere didn't exist. Light from the sun triggered chemical reactions that created them. The atmospheres of almost all the other planets in our solar system have the same photochemistry reactions. They hadn't been observed until now.

The first evidence for carbon dioxide in an exoplanet atmosphere was found in the WASP 39b ball of gas. An unknown molecule was absorbing the star's light as it passed through the planet's atmosphere.

The data on WASP-39b's light was analysed by a group of people at the University of St Andrew's in the United Kingdom. Chubb says that the large range of wavelength covered by the four different instruments allows for a complete picture of the atmosphere.

A range of atmospheric models were used to mimic the signal from the JWST. ric Hébrard said only models that included chemical reactions involving sulphur could reproduce the data. As soon as we each implemented our own chemistry, we were surprised.

If the planet was made from material created when the star system formed, the levels of sulphur dioxide would be much lower. Chubb says that light from the planet's star, WASP 39, has caused a chain of chemical reactions in the planet's atmosphere.

The University of Cambridge was not involved in the research. The results are a great demonstration of the capabilities of the JWST.

Identifying photochemical reactions on WASP 39b could help determine whether the planet formed further out from its star and moved inwards, or whether it formed at its current location and simply accumulated material there. Chubb says that early observations suggest that it formed far away from its star.

Hébrard said the find boded well for observing more compounds produced by photochemical processes. The first detection of a photochemical product is one way forward, even ifWASP-39b is very different than what we have on Earth.

One of the main goals of the JWST is to find signs of an exoplanet that could host life. The first step is to cover more in order to answer the biosignatures problems.

Arxiv.org/abs/2211.10490 and arxiv.org/abs/2211.10487 are references.

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