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Exoplanet Has Showers of Pebbles

Posted by CmdrTaco on from the gonna-need-a-thicker-umbrella dept.

mmmscience writes "The newly-discovered exoplanet COROT-7b has an unusual form of precipitation: rocks. Because it orbits so close to its sun, the temperature on its sun-facing side is around 4220 degrees Fahrenheit. That's hot enough for rocks to vaporize — not unlike water evaporating on Earth. And, like Earth, when the vapor cools in the upper atmosphere, it forms clouds and begins to rain. But instead of water, COROT-7b gets a shower of pebbles."

6 of 341 comments (clear)

  1. Re:Summary inaccurate by clone53421 · · Score: 5, Interesting

    True. Also, I'm wondering if "pebbles" is an appropriate description of the condensed rock or if it wouldn't be more aptly described as "sand" or even "dust". Raindrops stick together; depending on how quickly the rock condenses, it might not have time to grow very large. (Then again, it could grow like hail, if the rock was in the liquid state for any significant amount of time.)

    --
    Alexander Peter Kristopeit bought his basement from his mommy for one dollar.
  2. Fallout by mbone · · Score: 5, Interesting

    That has happened on Earth too. We call it Fallout.

    I am not kidding. A surface nuclear burst in the megaton range will vaporize millions of tons of rock and soil. This material will cool, condense, and and fall as
    little pebbles or hail. In this case, it's radioactive, but otherwise the physics is the same.

    1. Re:Fallout by mk_is_here · · Score: 5, Interesting

      To enjoy a natural one, without the radioactive waste, all you need is a volcano eruption.

  3. Meanwhile on COROT-7b by JohnHegarty · · Score: 5, Interesting

    Meanwhile on COROT-7b scientists find a new planet so cold that water would actually create "oceans" on the surface , and even freeze at the poles.

    They laugh at the though ever existing on that planet.

    --
    Cruise TT
  4. Conveyor-belt planet by FriendlyPrimate · · Score: 5, Interesting

    What I find interesting about this planet is that it's tidally locked with it's star, so one side is over 4000F, while the other is -370F. That could imply that the surface continuously evaporates on the hot side and condenses out of the atmosphere on the cold side. So the planet is essentially a conveyor belt always in the process of being destroyed and created. The contents of the entire planet could have gone through this process many times already.

  5. Re:Not unusual by fireslack · · Score: 5, Interesting

    Am I the only one who is deeply impressed that we even KNOW a planet is there? It is difficult to observe Mercury because of its proximity to the sun, but we can see a planet that is 1.7 Earth radii, 42 light years away, and is so close to its parent star, it has an orbital period of 20 hours. Hours! That means it is insanely close to its star. Solid rock or lava be damned. How about a pat on the back for finding any exoplanets at all?

    --
    This sig only exists because you are observing it.