Another first has been accomplished by the James Webb Space Telescope (JWST): a comprehensive molecular and chemical analysis of another planet's sky.
Orbiting a star about 700 light-years away, planet WASP-39 b is known as "hot Saturn," and its atmosphere was the focus of the telescope's highly sensitive array of equipment. Unlike previous findings from JWST and other space observatories such as Hubble and Spitzer, which reveal only a few components of this scorching planet's atmosphere, the latest readings offer a menu of atoms, molecules, and even indicators of active chemistry and clouds.
One of the researchers contributing to the new findings is Mercedes López-Morales, an astronomer at the Harvard & Smithsonian Center for Astrophysics. “The clarity of the signals from a range of different molecules in the data is astounding,” adds she.
López-Morales continues: “We expected to see many of these signals, but I was still stunned when I first saw the data.
The latest data also gives an idea of what these clouds on the exoplanets might look like up close: rather than evenly covering the planet, they're fragmented.
The results are encouraging in terms of JWST's potential to perform the wide range of studies on exoplanets -- planets around other stars -- that scientists hoped for. The atmospheres of smaller, stony planets, such as those in the TRAPPIST-1 system, can be studied as part of this.
According to astronomer Natalie Batalha of the University of California, Santa Cruz, who contributed and helped coordinate the new research, "We observed the exoplanet with multiple instruments that together provide a wide area of the infrared spectrum and a range of chemical fingerprints inaccessible until the JWST. ” “Data like this changes the game.”
A collection of five recently filed scientific publications available on the preprint website arXiv offers a full account of the discoveries. One of the groundbreaking discoveries was the first discovery of sulfur dioxide in the atmosphere of an exoplanet. This molecule is the result of chemical processes initiated by high-energy light from the planet's parent star. Similar processes are used on Earth to create the protective ozone layer in the upper atmosphere.
The unexpected discovery of sulfur dioxide "finally shows that photochemistry determines the environment of 'hot Saturns'," adds Diana Powell, a NASA Hubble scholar, astronomer at the Center for Astrophysics and a key member of the sulfur dioxide discovery team. Because photochemistry also affects climate, Earth has more in common with "hot Saturns" than previously thought.