Using the Hubble Space Telescope astronomers were able to confirm the colour of the closest known exoplanets to Earth. Located around 63 light years away the planet was discovered in 2005 but just this week it has been confirmed as blue; preliminary measurements indicated this but they were tentative. Scientists were able to conclude this by analysing spectrograph data from before, during, and after the planets transit of its star.
This is where any similarities to Earth end: unlike our mild temperatures, it can reach a scorching 2,000 degrees F and it is thought to rain glass (sideways) in 4,500 mph winds. It would be nice to think that the lush blue comes from great sweeping oceans like here at home, but it is through rather to come from drops on condensed silicates which scatter blue more than red light.
It turns out that HD 189733b isn’t a solid planet either, but rather a hot Jupiter. This class of exoplanets are much like Jupiter, hence the reference, but are much closer to their star causing them to be extremely hot. Examining the composition of such planets scientists are able to learn a lot about the climatology and physics of extraterrestrial worlds and thus aid in our search of habitable worlds.
It should be noted the image above is an artist rendering! (x)