An international team of astronomers has discovered an exoplanet located far from Earth that experiences unusual “iron rain.”
The Institute of Astrophysics of the Canary Islands (IAC) explained that the exoplanet named WASP-76b has daytime temperatures exceeding 2,400 degrees Celsius, hot enough to vaporize metals. However, at night, strong winds cool the iron, causing it to condense into iron droplets that fall onto the surface of this exoplanet.
This exoplanet is located 360 million light-years away from Earth.
This exoplanet is situated 360 million light-years from Earth, in the constellation Pisces. On this planet, a year lasts only 1.8 Earth days.
WASP-76b is tidally locked to its host star WASP-76, similar to how the Moon always shows the same face to Earth.
As a result, one half of this world is perpetually in daylight with average temperatures reaching up to 2,000 degrees Celsius, while the other half is always in the dark, “cooler” yet still experiencing extreme temperatures.
This tidal locking also facilitates strong winds surrounding the planet.
The remarkable conditions on WASP-76b were discovered using the Echelle Spectrograph and the ESPRESSO (Echelle Spectrograph for Rocky Exoplanets and Stable Spectroscopic Observations). This high-resolution instrument, managed by the IAC, is installed at the Very Large Telescope (VLT) in Chile.
Scientists utilized ESPRESSO to identify chemical variations between night and day on WASP-76b. This marks the first time such variations have been detected on an extremely hot planet.
The planet WASP-76b possesses an extremely bizarre environment – (Graphic: AI).
The abundant iron atoms in the atmosphere are mainly due to the extremely high temperatures on the day side of the planet, which vaporize the iron.
As the winds circulate to the night side, this iron condenses and falls as iron rain, similar to how water condenses and falls as rain on Earth.
The study of this intriguing planet has just been published in the scientific journal Astronomy & Astrophysics, adding another piece to the puzzle of how exoplanets operate beyond our solar system.
“Surprisingly, we did not observe this iron vapor at dawn,” said David Ehrenreich, a researcher at the University of Geneva and the lead author.
“Similar to the Moon’s orbit around Earth, this creates extreme temperature differences between day and night on the planet,” added Jonay I. González Hernández, another researcher.
Additionally, according to Núria Casasayas Barris, a researcher at the IAC and a PhD student at the University of La Laguna in Spain, giant planets are the best laboratories we have to study the extreme climates on exoplanets. With ESPRESSO, we can detect chemical changes by analyzing a small portion of the observable atmosphere.
