back to article Good luck pitching a tent on exoplanet WASP-76b, the bloody raindrops here are made out of molten iron

The weather is very strange on WASP-76b. Liquid iron rains down on one side of the exoplanet, every night. A paper describing the weird finding was published in Nature on Wednesday. Using the European Southern Observatory's Very Large Telescope in Chile, a large international team of astronomers led by the University of Geneva …

  1. Tom 7 Silver badge

    Raining molten iron?

    So a welding mask and jeans then!

    1. MyffyW Silver badge

      Re: Raining molten iron?

      Some kind of hat would be advised.

      1. Benchops

        Re: Raining molten iron?

        As the great Billy Connolly once said: There's no such thing as bad weather, only inappropriate clothing.

        1. ShadowDragon8685

          Re: Raining molten iron?

          In this case, I think the appropriate clothing is some kind of rocket- or impulse-powered robotic body, possibly with or not with a human mind uploaded into its cyberbrain, harvesting molten iron from the skies on a semiballistic trajectory.

          1. HelpfulJohn

            Re: Raining molten iron?

            Really? Why bother when *cold* iron is freely floating around in small chunks pretty much ubiquitously?

            Ram-mining gas giants for HE3 and other volatiles, I can see a use for as it would be much easier and more profitable. Ram-mining for iron is wasteful.

  2. Anonymous Coward
    Anonymous Coward

    like bad scifi

    At least having a name like WASP-76b should be enough to warn people away.

    1. Anonymous Coward
      Anonymous Coward

      Re: like bad scifi

      It's host star has something buzzing round it close and fast. WASP indeed.

      1. Captain Scarlet Silver badge

        Re: like bad scifi

        Shame its incorrectly named, all the mysteron West Ham Fans live there hence their chucking iron in the air within bubbles!

      2. TRT Silver badge

        Re: like bad scifi

        Ah, that'll be the the Type-B star at the centre of the system; Jamjar.

  3. Joe W Silver badge

    Hell of a


    ... and paper to write. It sounds like they had lots of fun figuring that out and writing the paper. Inspiring - especially if you are a band like Hammerfall or Manowar...

    Science is great (at times).

    1. Throatwarbler Mangrove Silver badge

      Re: Hell of a

      Iron!? Pshaw! Manowar fans are satisfied with nothing less than steel!

      1. Sorry that handle is already taken. Silver badge
    2. phuzz Silver badge
      Thumb Up

      Re: Hell of a

      My first thought was that if the rain is iron, then you should be able to float a Lead Zeppelin in the atmosphere.

      1. Anonymous Coward
        Anonymous Coward

        Re: Hell of a

        In over 2000 degrees hot air?

        1. phuzz Silver badge

          Re: Hell of a

          Ok, that might pose a slight problem.

          Maybe paint it white, and give it one of those little handheld fans?

  4. Zog_but_not_the_first


    With just a nudge along the first row transition elements we could have a chorus of "It's raining Mn".

  5. israel_hands

    Heavy Metal Thunder?

    Is there a chance it'll explode into spaaaa-aaace?

  6. Zebo-the-Fat


    If it's tidally locked (so not rotating) and the iron is being transported from the hot side to the cold side, it will eventually all be on the cold side so the iron rain will stop. Am I missing something??

    1. mr.K

      Re: Puzzled!

      That it is a gas giant.

    2. KittenHuffer Silver badge

      Re: Puzzled!

      The core of the planet is a molten ball of the elements whose boiling point is lower than the night side temperature. Anything that boils at lower than the night side temperature is part of the 'gas' that makes up the atmosphere.

      What is happening is that the day side is hot enough to boil elements out of the core, then strong winds carry these around to the night side, where they cool off enough to precipitate out and return to the core as liquid.

      Eventually thermal currents in the liquid will carry this material back through the core to the day side where the process will repeat.

    3. Cuddles Silver badge

      Re: Puzzled!

      "If it's tidally locked (so not rotating)"

      It is rotating. Being tidally locked means its rotation period is equal to its orbital period.

      1. FrogsAndChips

        Re: Puzzled!

        Since none of you specified the reference frame, you are both right and wrong.

        1. Anonymous Coward
          Anonymous Coward

          Re: Puzzled!

          Clearly the default rotational frame of reference is the Earth's moon.

        2. Brewster's Angle Grinder Silver badge

          Re: Puzzled!

          "Since none of you specified the reference frame, you are both right and wrong."

          In low energy situations, you can separate an inertial frame from a non-inertial one - e.g. Foucault's pendulum will reveal you are in a rotating frame embedded in a large volume of flat space.

      2. JCitizen
        IT Angle

        Re: Puzzled!

        Why couldn't it be rotating on its axis pointed to the star? I seem to remember one of the planets in our system does that. Boffins say they think it got hit by something big in the past to knock it off the usual axis.

        1. Cuddles Silver badge

          Re: Puzzled!

          Because that's not what "tidally locked" means. It's certainly possible for a planet (or other body) to do that, but it wouldn't be tidally locked if it did. The planet you're thinking of is Uranus, which is tipped over at nearly 90 degrees compared to pretty much everything else. But it's not tidally locked to the Sun, so different parts of it still get different amounts of light at different times of its year.

          As for how it happened, the most recent thinking is that it probably couldn't have been a simple collision with another large body, since a big enough hit to cause the tilt should have outright destroyed it. Something pretty major must have happened to it, but it was likely rather more complicated than previously thought.

          1. HelpfulJohn

            Re: Puzzled!


            Why "... something pretty major ..."?

            Uranus is a looong way out, Sol's influence isn't overwhelmingly huge, perhaps the largest pool of collapsing, whirling stuff in the original cloud out there just happened to be rotating "sideways" and no reat force happened to be around to stop it doing so?

            Random chance, a small eddy compressing into a larger on simply because it was the only "force" of any consequence in the vicinity. Uranus's moons would have followed it, of course, as they. too, would have condensed out of the tipped primordial whirly.

            And why have no other planets "fallen over" like Uranus? Well, techincally they have, just to a smaller degree. Non of their rotational axes are exactly orthogonal to the Sun's equatorial plane, which is assumed to have been the plane of rotation of the original disc. Uranus is just the outlier.

            No magic, no Giant Impactor, no mysterious series of not-so-giant Impactors needed, just simple physics doing its thing.

            A soft-merging of two condensation sites co-orbiting explains the Moon and Triton, too. The System is huge, it's been around for a colossal amount of time, it has *room* for things like these. "Giant Impactors" are idiotic.

            1. JCitizen
              Thumb Up

              Re: Puzzled!

              Thanks to HelpfulJohn and Cuddles for those responses, I now have a better grasp on orbital planetary birth, and the exceptions there of.

    4. Grikath

      Re: Puzzled!

      The "it's a gas giant" bit is correct..

      Jupiter ( and for that matter, any gas giant) will have Iron Rain somewhere as well. With enough metal content, the inner temperatures will make it inevitable. The difference with WASP is that one side of the planet gets stoked up hard enough that this iron actually reaches the surface layers where we can detect it, instead of being hidden by several 1000's of miles of boring methane, ammonia, and water ice.

  7. Mark 85 Silver badge

    Scratch that one from the "places to visit list".

    I'm not a hot weather fan anyway...on the other hand, can we send all the flaming idiots there?

  8. Chris G Silver badge

    Hell of a tan

    And going for a refreshing shower after a day in the sun, not really an option.

  9. israel_hands

    If Michael Moorcock had ever collaborated with Iron Maiden on an album, there would have been a song called WASP-76b about a planet where it rains pure METAL!!! every single night.

  10. SVV

    The "night" side is colder dropping to 1,500°C

    The aliens that live there are tough enough to cope with it though. They're hard as nails.

    1. John Jennings

      Re: The "night" side is colder dropping to 1,500°C

      Likely they are nails

    2. I ain't Spartacus Gold badge

      Re: The "night" side is colder dropping to 1,500°C

      I strongly dispute the use of the word "colder"!

      I feel that we should substitute at least "less warm" into the sentence in question.

      Can one buy asbestos umbrellas?

      1. Thrudd the Barbarian

        Re: The "night" side is colder dropping to 1,500°C

        Only in jurisdictions where it's use and sale is not banned. Try the states.

  11. Neurons for Kryton


    ...A triple max-prison,

    A no daylight slam,


    1. Anonymous Coward
      Anonymous Coward

      Re: Riddick...

      Considering they were able to run around on the surface at night, it was obviously not as warm as this planet's 1500C night!

  12. John Brown (no body) Silver badge
    Thumb Up

    And no one...

    ...has mentioned Iron Sky yet? Shame on you all.

  13. the Jim bloke Silver badge

    So 640 light years away

    and they can detect raindrops..

    and to think they used to brag about reading newspaper headlines from orbit..

    1. Anonymous Coward
      Anonymous Coward

      Re: So 640 light years away

      As the article puts it, they "detected a whiff of iron vapour on one side". At these kinds of distances, the star is effectively a dot, even through our best telescopes - how can they tell one side of the planet from another? Typically they look for planets based on changes in the star's brightness as the planet moves in front of it, and estimate the composition by looking at the changes in the emission spectra of the star. While producing some interesting articles like this one, I strongly suspect that much of what we "know" about exoplanets will eventually be disproven, likely by direct observation (i.e. sending a probe there, which obviously isn't happening anytime soon).

      1. 2+2=5 Silver badge

        Re: So 640 light years away

        > how can they tell one side of the planet from another?

        They use a clock. Or a calendar if it's rotating particularly slowly.

      2. vtcodger Silver badge

        Re: So 640 light years away

        "how can they tell one side of the planet from another?"

        Doppler shift in Iron emission lines perhaps. It'll presumably be the sum of planetary rotation round its star, and its "daily rotation". It'll (presumably) be slightly different at different points on the planet's orbit (and at different points in the Earth's orbit as well). Can "they" really measure things that finely and sort them out? I haven't the slightest.

    2. Anonymous Coward
      Anonymous Coward

      Re: So 640 light years away

      Just thinking about the weather forecast..

      "So the weather for tomorrow - 640 years ago - will warm to hot with very heavy rain.."

  14. Winkypop Silver badge

    Raining molten iron?

    Mankind: Hold my beer...

  15. Vin

    ... from a lacerated sky

    Just wanted to say that I appreciate the Slayer reference

    1. Michael H.F. Wilkinson

      Re: ... from a lacerated sky

      and those skies are our best bet to find an Iron Butterfly

  16. DJO Silver badge

    Apologies to Burt Bacharach

    Raindrops keep burning through my head

    And that does mean my eyes will be melting and turning red

    Frying's not for me

    'Cause I'm never gonna stop the rain by complaining

    Because I'm free

    Lounging on Wasp 76b

    1. JCitizen

      Re: Apologies to Burt Bacharach

      I could hear the tune in my head while reading that! HA!

  17. Denarius Silver badge


    No chance. No nonconductive particles rubbing electrons off each other, despite electrifying atmosphere. Also high probability of short circuits

  18. Aristotles slow and dimwitted horse Silver badge

    Whilst reading this I was reminded of the prison planet in that excellent National Geographic documentary The Chronicles of Riddick.

  19. Anonymous Coward
    Anonymous Coward

    Iron curtain

    If the drop in temperature causes iron precipitation, probably it is happending around the shadow edge and not making it much further round to the night side (I say "probably" -- I have no idea)? Creating a giant ring of iron curtain. Hope Putin doesn't get ideas.

  20. iron Silver badge

    I refute these claims that I have turned into a liquid and rain on planet WASP-76b as FAKE NEWS!

    I've never been near that planet and didn't touch it's molten core.

  21. HammerOn1024

    Iron Mining

    Well then! Orbital iron mining will be the way to go! Just drop a ceramic caldron down to collect the molten iron, hoist, dump in the holding hopper and repeat.

    One can take the hopper back to a refinery straight away; no smelting required.

  22. simonb_london

    It does indeed seem like a bad place to pitch a tent. Looks like I'll be taking the caravan then.

    1. Annihilator Silver badge

      On the plus side, rain has the benefit of deterring the midges. I can only imagine what molten iron rain would do to them.

      1. I ain't Spartacus Gold badge

        My abiding memory of 70s/80s caravan holidays was sitting inside because it was pouring, listening to the drumming of the rain on the roof and my Mum's New Seekers tapes. So I guess the upside of iron rain is that the noise might drown out the music.

        1. TRT Silver badge

          Ha ha. I wish I could upvote that more than once.

          I'm currently rediscovering Barclay James Harvest. I believe it could be a contemporary antidote, like dock leaves and nettles growing near each other.

      2. John Brown (no body) Silver badge

        "On the plus side, rain has the benefit of deterring the midges. I can only imagine what molten iron rain would do to them."

        Not much. Or have you not met the midges of North West Scotland?

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