A gas giant exoplanet has become the best explored planet outside of our solar system, thanks to the James Webb Space Telescope (otherwise known as JWST or Webb) and due to the thorough molecular and chemical analysis. WASP-39b is similar to our solar system’s Saturn and is 700 light years away from our sun, and orbits 7 million kilometres away from its parent star (over eight times closer than the distance between our sun and Mercury). It is in the orbit of one of Virgo’s (a constellation) stars and has already been in the news in the summer of 2022 for carbon dioxide being detected in its atmosphere. Studies carried out by an international team involving over 100 scientists from around 50 different institutions based on the James Webb Space Telescope’s findings of the planet has enabled astronomers and astrophysicists to make conclusions about WASP-39b’s formation history just based on details of its atmosphere.

However, the observation of WASP-39b has been part of a bigger project – to test the capabilities of the James Webb Space Telescope. The findings have been a huge success to the astronomy world!

WASP-39b is surrounded by clouds containing sulphur and silicates, and sulphur dioxide is produced through a reaction similar to the one which produces ozone in the Earth’s atmosphere – the chemicals interact with the light of the parent star. Sulphur dioxide is vital for photochemical reactions – the intensity of starlight is hoped to be used as a tool to study photochemical reactions, such as how sulphur dioxide is produced, along with testing methods to help detect life by using atmospheric analysis and comparing oxygen levels to models.

The findings have not only revealed signs of active chemistry, but the results have seen carbon dioxide at a higher resolution by providing twice as much data than previous observations. These atmospheric analyses also could tell us about the foundation building blocks of the planet! The researchers analysing data sent from the James Webb Space Telescope have inferred that the planet must have formed from collisions of several smaller planetesimals further away from the trajectory where it currently orbits, which are large rocky bodies that enriched the chemical makeup of WASP-39b by enriching its atmosphere in rocky material.

Unfortunately, WASP-39b’s temperatures soar to a sweltering 900 degrees Celsius as it orbits very close to its star, meaning that it cannot host extra-terrestrial life as we know it; no little green aliens QUITE yet!

Fortunately, the discovery has been an extremely exciting moment as the instruments tested of the telescope have a huge potential in the future!