Scientists believe it may ‘rain iron’ on distant planet

A planet where it might rain iron has been discovered by scientists.

Researchers have identified an iron absorption line on the ultra-hot exoplanet, a planet outside our solar system, called Wasp-76b.

Published in the Nature journal, the findings suggest it could rain iron on the nightside of the planet 390 light years away.

Some days its surface temperature exceeds 2,400C, hot enough to evaporate metals.

But at night the cooler temperatures mean the vapour turns into drops of iron.

This is the first result with the high resolution Echelle Spectrograph for Rocky Exoplanets and Stable Spectroscopic Observations (Espresso).

Astrophysicists have identified chemical variations between day and night on the planet.

They detected the trace of iron vapour just at the division between the daytime and the night-time sector of the planet.

David Ehrenreich, a researcher at the University of Geneva and the first author of the article, said: “However, surprisingly we do not see this iron vapour at dawn.

“The only explanation possible for this phenomenon is that it rains iron on the dark side of this exoplanet with extreme conditions.”

Jonay I Gonzalez Hernandez, Ramon y Cajal researcher at the Instituto de Astrofisica de Canarias, Spain, said: “Just like the moon around the Earth, this planet always keeps the same face towards its star as it rotates around it, which causes this extreme difference in temperature between day and night on the planet.”