The alien planet HD 189733b is a beautiful blue dot in a sea of inky blackness, just like Earth. But that's where the similarities between the two worlds end.

For starters, HD 189733b is much bigger and hotter than Earth; it's about the size of Jupiter and zips around its host star in just 2.2 Earth days. That orbit is so close that the exoplanet is probably tidally locked, always showing one face to its star, just as the moon always shows one face (the near side) to Earth.

And then there's the weather. The winds on HD 189733b (which lies about 63 light-years from Earth, in the constellation Vulpecula) blow at up to 5,400 mph (8,700 km/h) — about seven times the speed of sound. And if that's not crazy enough for you, scientists think the rain on this world is made not of water, but of molten glass.

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