Astronomers have identified two unexpected chemical elements within the atmospheres of two blazing exoplanets as liquid iron and gems are falling from the sky.
The exoplanets, which orbit distinct stars outside our solar system, are extremely hot gas giants called WASP-76b and WASP-121b. Astronomers have used the European Southern Observatory’s Very Large Telescope to detect high-altitude barium in the atmosphere of every exoplanet.
Barium is the heaviest element ever found in the atmosphere of an exoplanet. Scientific Journal Astronomy and astrophysics A study published Thursday detailed the discovery.
With each spin, WASP-76b and WASP-121b seem alien to scientists.
“The intriguing and counterintuitive part is why is there such a heavy element in the upper atmosphere of these planets?” study author Tomas Azevedo Silva, a doctoral student at the university’s Institute of Astrophysics and Space Sciences, said in a statement. .
“In a way it was an ‘accidental’ discovery. We weren’t expecting or looking for barium in particular and had to verify that this actually comes from the planet, as it has never been seen on any exoplanets.”
The two exoplanets are similar in size to Jupiter, the largest planet in our solar system, but they have extremely hot surfaces, well over 1,000 degrees Celsius.
The high temperatures of WASP-76b and WASP-121b stem from the fact that each planet lies close to its host star, completing its orbit in a day or two.
WASP-121b was initially discovered in 2015, and is about 855 light-years from Earth. The exoplanet has a glowing atmosphere of water vapor, and the strong gravitational force of the star orbiting it distorts it into a rugby ball.
The planet is gradually closed, which means that it is always on the same side facing the star. It is similar to how the moon revolves around the earth. On the day side, temperatures start at 2,227°C in the deepest layer of the atmosphere and reach 3,227°C in the upper layer.
Scientists first discovered WASP-76b in 2016. It orbits a star in the constellation Pisces, 640 light years from Earth. The tides also hinder this exoplanet, so the temperature exceeds 2426 degrees Celsius on the day side.
The scorching nature of exoplanets has given them unusual features and a climate that sounds like science fiction. Scientists believe liquid iron is falling from the sky on WASP-76b, while liquid mineral and gem clouds are forming on WASP-121b.
The illustration shows an image of the night face of exoplanet WASP-76b, where liquid iron is raining from the sky. M. Kornmeiser/European Southern Observatory
The discovery of barium in the upper atmosphere of the two planets surprised researchers. The element is 2.5 times heavier than iron.
“Given the high gravity of the planets, one would expect heavy major elements such as barium to rapidly fall to the lower layers of the atmosphere,” said study co-author Olivier Demangon, a postdoctoral researcher at the Institute of Astrophysics and Sciences. University of Porto area.
Finding barium in the atmospheres of two exoplanets could indicate that the super-hot gas giants have more unusual features than we thought.
On Earth, barium appears in the night sky as a bright green when fireworks explode. But scientists aren’t sure of the natural process that causes this heavy element to appear high in the atmosphere of these gas giants.
The research team used the ESPRESSO instrument, or Echelle Spectrograph for Rocky Exoplanets and Stable Spectrographs, on the Very Large Telescope in Chile, to study starlight as it passes through each planet’s atmosphere.
“Being gassy and hot, it has a very expansive atmosphere,” Demangon said. “Thus, they are easier to observe and study than those on smaller or cooler planets.”
Future telescopes will also be able to see more detail in the atmosphere layers of exoplanets, including rocky Earth-like planets, to unlock the mysteries of unusual worlds scattered across the galaxy.
