Telescopes such as Hubble have previously revealed parts of the heated gas planet Wasp-39b’s atmosphere. But with James Webb’s more sensitive instruments, astronomers have been able to get a more complete picture of the molecular and chemical composition. Water, sulfur dioxide, carbon monoxide, sodium and potassium have been identified.
The data also gives an indication of how the clouds form, writes the European space agency Esa in a press release.
Wasp-39b has roughly the same mass as Saturn. It follows a much tighter orbit around its star, tighter than Mercury around the Sun.
The researchers now hope that the breakthrough will pave the way for in-depth studies also of other exoplanets – planets outside our solar system.
“This data is absolutely decisive,” says Natalie Batalha, an astronomer at the University of California in the United States, in the press release.
Among several unique discoveries linked to exoplanets is sulfur dioxide, which is a consequence of a similar chemical reaction that created the Earth’s ozone layer.
“It’s the first time we’ve seen concrete evidence of photochemistry – chemical reactions initiated by bright starlight – on exoplanets,” said Shang-Min Tsai, a researcher at Oxford in the UK.