About the episode
Exoplanet WASP-43b is similar in size and mass to Jupiter, but looks absolutely nothing like the well-known gas giant.
The planet orbits its star extremely closely, causing it to be permanently day on one side and permanently night on the other. A year on the planet, i.e. the time in which the planet orbits the star once, therefore only takes about 19.5 hours.
That makes it easier to study the planet for a whole year. Although you still need extremely good instruments. And they are located on the James Webb Telescope, among others.
This has now made it possible to take a good look at the dark night side of the planet and to create a temperature map of the entire planet. The chemical composition of the atmosphere has also been measured. There appears to be water vapor in the atmosphere on both the day side and the night side.
It was already known that methane cannot occur on the dayside of the planet. It’s simply too hot there. But the new measurements show that there is no methane on the night side either. And that was a big surprise for the researchers. At 600 degrees, the night side is theoretically cool enough for methane production.
The researchers believe that extreme winds with speeds of up to 7,500 kilometers per hour are the reason that no detectable amounts of methane can be formed.
It is the first time that scientists have so clearly mapped the temperature and composition of the atmosphere of an exoplanet. In the future they want to do this with more exoplanets.
Read more about the research here: Surprise: no methane on night-side exoplanet WASP-43b
Tags: surprise astronomers find methane night side exoplanet
