An anonymous reader quotes a report from Ars Technica: Astronomers have detected over 5,800 confirmed exoplanets. One extreme class is ultra-hot Jupiters, of particular interest because they can provide a unique window into planetary atmospheric dynamics. According to a new paper published in the journal Nature, astronomers have mapped the 3D structure of the layered atmosphere of one such ultra-hot Jupiter-size exoplanet, revealing powerful winds that create intricate weather patterns across that atmosphere. A companion paper published in the journal Astronomy and Astrophysics (PDF) reported on the unexpected identification of titanium in the exoplanet’s atmosphere as well. […]
This latest research relied on observational data collected by the European South Observatory’s (ESO) Very Large Telescope, specifically, a spectroscopic instrument called ESPRESSO that can process light collected from the four largest VLT telescope units into one signal. The target exoplanet, WASP-121b — aka Tylos — is located in the Puppis constellation about 900 light-years from Earth. One year on Tylos is equivalent to just 30 hours on Earth, thanks to the exoplanet’s close proximity to its host star. Since one side is always facing the star, it is always scorching, while the exoplanet’s other side is significantly colder.
Those extreme temperature contrasts make it challenging to figure out how energy is distributed in the atmospheric system, and mapping out the 3D structure can help, particularly with determining the vertical circulation patterns that are not easily replicated in our current crop of global circulation models, per the authors. For their analysis, they combined archival ESPRESSO data collected on November 30, 2018, with new data collected on September 23, 2023. They focused on three distinct chemical signatures to probe the deep atmosphere (iron), mid-atmosphere (sodium), and shallow atmosphere (hydrogen). “What we found was surprising: A jet stream rotates material around the planet’s equator, while a separate flow at lower levels of the atmosphere moves gas from the hot side to the cooler side. This kind of climate has never been seen before on any planet,” said Julia Victoria Seidel of the European Southern Observatory (ESO) in Chile and the Observatoire de la Cote d’Azur in France. “This planet’s atmosphere behaves in ways that challenge our understanding of how weather works — not just on Earth, but on all planets. It feels like something out of science fiction.”