While the alien planet, referred to as HD 189733b, is as beautifully blue as Earth, it’s only the image that make the two similar. In fact, they are as different as you can imagine it to be.
One of its stark differences is the size. Located about 63 light years away from Earth, in the Vulpecula constellation, HD 189733b is much bigger than Earth, and is estimated to be about the size of Jupiter. It orbits its host star in just 2 days, and it is doing so very closely that the exoplanet is most likely tidally locked and showing only once face to its star, similar to how the moon always shows one face to Earth. In addition, the alien planet is very hot compared to Earth.
Another difference is the weather. The winds on the alien planet can reach speeds up to 5,400 mph or 8,700 km/h. To put it in perspective, it is about seven times faster than the speed of sound. What’s more, scientists also think that rain on the planet is not made of water but molten glass.
Why then does the planet have an Earth-like appearance? According to NASA, the cobalt blue colour is not a reflection of tropical oceans, like on Earth, but from a hazy atmosphere which contain high clouds with silicate particles.
Image source: http://space.com