Mar 17, 2020 - Science

Iron rain on an alien world

Artist's illustration of the iron rain

Artist's illustration of the iron rain. Photo: ESO/M. Kornmesser

A telescope in Chile has found a world 640 light-years from Earth that rains liquid iron, adding to the strange tapestry of planets far from our own.

Why it matters: The more that scientists understand about planets circling other stars, the closer they get to finding out just how unique (or common) our solar system — and therefore life — is.

Details: The world, named WASP-76b, is tidally locked to its star, like the Moon is to Earth. The planet’s day side gets so hot that iron evaporates into its atmosphere.

  • Winds blow strong enough on the planet that the iron moves from the day side to the night side of the world where it then cools.
  • As the atmospheric iron cools, it rains onto the cooler night side.
  • The new discovery was made using the ESPRESSO instrument on the Very Large Telescope in Chile.

The big picture: WASP-76b is only one of the many weird exoplanets — planets circling other stars — that are fascinating scientists today.

  • The planet HD 189733b has winds that blow up to 5,400 mph and likely rains glass.
  • Another world, HD 209458b, orbits so close to its star that its thick atmosphere is evaporating and the planet appears to have a tail like a comet stretching out behind it.
  • 55 Cancri e — located about 41 light-years away — is masked by a thick atmosphere that may hide a surface covered entirely in lava.

The bottom line: While many scientists are hunting for another Earth light-years away from our solar system, hundreds of other planets with their own properties are still worthy of study.

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