Astronomers discovered a surprising chemical element in the atmosphere of two exoplanets that are hotter than expected. It is where liquid iron and gems fall from the sky.
These two exoplanets orbit separate stars outside our solar system and are called ultrahot gas giants WASP-76b or WASP-121b. To detect barium in the atmospheres of the exoplanets, astronomers used the Very Large Telescope from the European Southern Observatory.
Barium is the heaviest element ever found in an exoplanet’s atmosphere. A study was published by Astronomy and Astrophysics on Thursday.
Scientists find WASP-76b more bizarre with each new revelation.
“The puzzlement and counterintuitive part of this study is: Why is there so much heavy element in these upper layers of the atmosphere of planets?” stated Tomas Azevedo Silva (lead author of the study), a doctoral student at the University of Porto and Institute of Astrophysics and Space Sciences, Portugal in a statement.
This was not an accident. Since it was not expected or looked for, in particular, we had to verify that the barium was indeed coming from the planet.
Although they are roughly the same size as Jupiter, the largest planet in our solar system, both exoplanets have extremely high surface temperatures, well over 1,832 degrees Fahrenheit (1,001 degrees Celsius).
WASP-76b’s high temperatures and WASP121b’s record-breaking heat come from the fact each planet orbits its star close enough to cause them to experience extreme temperatures.
WASP-121b was discovered for the first time in 2015. It is approximately 855 light-years away from Earth. The exoplanet is covered in a glowing water vapor atmosphere and the strong gravitational pull from the star it orbits has deformed it into the form of a football.
Tidally locked means that the same side of the planet faces the star. This is similar to the way our moon orbits Earth. Dayside temperatures reach 5,840 F (3.227 C), at the top layer, and 4,040 F (2.227 C), at the bottom layer.
In 2016, scientists spotted WASP76b for the very first time. It orbits a star in the Pisces constellation, 640 light years from Earth. This exoplanet also has a tidal lock, so temperatures on its dayside, facing the star, exceed 4,400 F (2.426 C).
Exoplanets’ hot nature has given them weather and unusual features that look like science fiction. Scientists believe liquid iron rains from WASP-76b’s sky, while liquid gems and metal clouds form on WASP121b.
Researchers were surprised to discover that barium was found in the upper atmospheres of all planets. Barium is 2 1/2 times more heavy than iron.
“Given the gravity of the planets we would expect heavy elements such as barium to quickly sink into the lower layers of our atmosphere,” Olivier Demangeon (postdoctoral researcher at the University of Porto and Institute of Astrophysics and Space Sciences, Portugal) said in a statement.
The presence of barium in both exoplanets’ atmospheres could indicate that the ultrahot gas giants may have more peculiar features than previously thought.
Barium is visible in the night sky as a bright green color when fireworks go off. Scientists aren’t certain what causes the heavy element to appear so high within the atmosphere of these giant gas giants.
To study the starlight passing through each planet’s atmosphere, the research team used the ESPRESSO instrument (or Echelle SPectrograph For Rocky Exoplanets & Stable Spectroscopic Observations), which was installed at the Very Large Telescope in Chile.
Demangeon stated that because they are hot and gaseous, their atmospheres can be very long and are therefore easier to study and observe than smaller planets.
Future telescopes will be able also to see more detail within the atmospheric layers of exoplanets to help unlock the secrets of strange worlds throughout the galaxy.