And now for the intergalactic weather

Alanis Morissette famously interpreted a rained-out wedding as “ironic.” It isn’t clear if Morissette consulted a weather forecast in the hours leading up to the ceremony, but one thing is certain: Doing so would have greatly reduced the chances of a ruined wedding.

That said, who are we to discount the unpredictability of weather?

Meteorology is a difficult job. Even for the most accommodating global citizen, it can be hard to forgive and forget a poor-performing forecaster — a fact that has created a stigma that dates to the days when people watched television to receive their forecasts.

Courtesy of NASA, ESA, CSA, Ralf Crawford (STScI) and iStock.com/mokee81.

Simply, public trust can be hard to maintain for meteorologists.

Compounding this issue is a recent NASA undertaking: The agency will create its own forecasts for planets in different galaxies. By gathering precise brightness measurements over a broad spectrum of mid-infrared light, combined with 3D climate models and previous telescope observations, investigators from the NASA Webb Mission team have used the James Webb Space Telescope to map the weather on a Jupiter-size, gas-giant exoplanet 280 light-years from Earth, called WASP-43b.

The exoplanet is only 1.3 million miles away from the sun. For context, Mercury, the closest planet to our sun, is 40.5 million miles away from the great lightbulb in the sky and ~3% the size of WASP-43b. With an orbital period of 19.5 h, even a middling meteorologist could predict the presence of extreme weather patterns within its atmosphere. But NASA was curious to see just how extreme things might be.

Studying the exoplanet is almost impossible using normal telescopy. It just so happens, however, that conditions are perfect for phase curve spectroscopy — a technique that can be used to measure tiny changes in the brightness of a star-planet system as a planet orbits its star. Using the telescope’s mid-infrared instrument to measure light from the planet’s system every 10 s for more than 24 h, the scientists calculated temperatures for both sides of the planet, while creating a temperature map across the planet’s surface. Like the moon to Earth, WASP-43b is tidally locked, meaning that the sun only ever sees one side of the planet’s swirling mass of hot gas.

The team found the hottest mass of gas to be 1250 °C (2300 °F), while the coolest soared only to a brisk 600 °C (1100 °F).

NASA and its Webb Mission team may be more apt to look beyond the stars for weather forecasts than they are to report the weather at home. Still, could NASA drive meteorologists on Earth into high gear when it comes to accurate forecasts?

Another possibility is that NASA’s work will catalyze a change to Morissette’s ironic lyrics. After all, what’s more ironic than having a better grasp of what’s happening on other worlds rather than your own?

The research was published in Nature Astronomy (www.doi.org/10.1038/s41550-024-02230-x).