Hubble has helped astronomers measure changes in the weather on an exoplanet – and it won’t be topping anyone’s travel lists. Forecasts for the planet Tylos predict a gigantic hurricane today with a top of over 3,000 °F (1,650 °C), followed by a strong chance of showers of molten iron tonight.
Astronomers spend a lot of their time hunting for exoplanets that could be potentially habitable. We’re looking for rocky worlds with a stable climate, comfy temperatures, plenty of water, shelter from radiation, and preferably a lack of asteroid Armageddons. Sure, we might not be dropping in on these planets ourselves any time soon, but they give us the best chance for maybe spotting alien life from their technology – or their farts.
Tylos, however, is none of those things. Officially known as WASP-121 b, it’s a scorching hot Jupiter-sized planet that orbits its star so closely that it’s on the verge of being torn apart by the intense gravity. Being that close, a year lasts just 31 hours, and of course, you can’t graze the surface of a cosmic nuclear reactor without getting a bit toasty – days on Tylos get hot enough to vaporize iron.
Scientists have in the past taken snapshots of weather systems on exoplanets, but in a new study, a team has modeled the weather on Tylos changing over time. The researchers gathered Hubble observations of the planet captured in 2016, 2018 and 2019, then reprocessed and compared them to see how things were changing over the years. Next, they ran sophisticated atmospheric computer models to check which scenarios best explained what they were seeing.
And the results were pretty intense. Tylos is tidally locked, meaning the same side always faces its host star, creating an absolutely broiling side of nonstop daylight and a chilly eternal night around the back. That temperature differential of course makes for a crazily turbulent atmosphere where hurricanes are constantly flaring up, raging across half the planet at once, then being ripped apart.
If you thought hurricanes on Earth were bad, on Tylos the temperatures in these storms can soar to almost 3,410 °F (1,877 °C). There are actually stars cooler than this. Oh yeah, and the clouds aren’t made of water vapor but iron, which rains back down on the night side.
As a gas giant, there’s no surface on Tylos to stand on anyway, so habitability for life is out of the question before we even get to the hellish hurricanes. But still, the team says that this work can help us characterize exoplanet weather better, and may help the hunt for more liveable planets in future.
"The assembled data-set represents a significant amount of observing time for a single planet and is currently the only consistent set of such repeated observations," said Quentin Changeat, a principal investigator on the team. “The information that we extracted from those observations was used to infer the chemistry, temperature, and clouds of the atmosphere of WASP-121 b at different times. This provided us with an exquisite picture of the planet changing over time.”
The research has been accepted for publication in the Astrophysical Journal. Models of Tylos's weather can be seen in the video below.
Source: NASA
