Clear atmosphere defeats the exoplanet haze
NASA’s Webb telescope has found a surprisingly clear atmosphere around a hot sub-Neptune. TOI-421 b now has better air-quality data than several holiday rentals.
The planet lies about 244 light-years away and reaches roughly 1,340 degrees Fahrenheit. Scientists found water vapour, plus possible signs of carbon monoxide and sulfur dioxide. The brochure describes this as character.
Researchers expected something heavier and hazier. Instead, the atmosphere contains lots of hydrogen and resembles the material of its host star, as though the planet furnished itself from the parental loft.
“The sky is clear with scattered opportunities for instant evaporation,” said Dr Celeste Gasbag, Chief Forecaster for Places Without Deckchairs. “Visitors should pack light and remain on Earth.”
Sub-Neptunes rank among the galaxy’s common planets, yet our solar system has none. Nature apparently built the popular model everywhere except the showroom where humanity could inspect one.
Webb measured starlight passing through the atmosphere. Different gases left signatures in that light, turning a distant transit into the universe’s most expensive breathalyser.
Scientists now want to study more hot sub-Neptunes. TOI-421 b welcomes the attention but has declined to install a pool until temperatures become less pool-shaped.
Read the real story: NASA’s report on Webb and TOI-421 b.
The clear view should help scientists understand a type of planet that refuses to exist locally, which is at least tidier than discovering it next door. TOI-421 b will remain a poor holiday option. The travel office has promised no hidden fees, because every fee would evaporate before checkout.
