merelygifted:

(via Scientists identify rain of molten iron on distant exoplanet | Science | The Guardian)

Wasp-76b is what astronomers call an exoplanet, one that orbits a star outside our solar system. Scientists have discovered that the local weather conditions include 2,400C temperatures, winds in excess of 10,000mph and a steady pelting of iron rain.  …

…  Wasp-76b, which is 640 light years away in the constellation of Pisces, [has a Sun which] is an ultra-hot gas giant. It orbits its star at about 3% of the distance between the Earth and the Sun, resulting in scorching surface temperatures and the weird phenomenon of molten iron falling from the sky.  …

…  Because the planet is so close in, it is “tidally locked” (like the Moon’s orbit about Earth) and only only ever shows one face, its day side, to its parent star, while its cooler night side remains in perpetual darkness.

On the day side, which is 1,000 degrees hotter, molecules separate into atoms, and iron evaporates into the atmosphere to form metallic clouds. The extreme temperature difference between the day and night sides produces ferocious winds that carry the iron vapour to the cooler night side, where temperatures decrease to about 1,500C and the iron condenses and falls as rain that constantly peppers the planet’s gas surface and vanishes beneath it.  …

…  The latest observations…compare the gases present in the leading edge of the planet as it passes across the face of the star and the trailing edge.

For Wasp-76b, this revealed iron vapour at the leading edge, where the prevailing 10,000mph wind would be blowing from the day side into the night side. But the signal was absent from the trailing edge, suggesting that all the iron had rained down on the night side by the time the circulating wind came back around.  …