Skies are clear and blue on an extrasolar planet 14 times more massive than Earth.

Using the Large Binocular Telescope in Arizona, a team led by Valerio Nascimbeni at the University of Padua, Italy, studied ultraviolet and infrared light coming from the dwarf star GJ3470, 31 parsecs from Earth. By watching the star dim as a known planet passed in front of it, the astronomers could probe light scattered by the planet's atmosphere.

The data suggest that the planet has a blue, cloud-free sky, which could help to reveal the composition of its atmosphere. The data are also precise enough to suggest that ground-based telescopes can now be used to discover Earth-sized planets around similar stars, rather than relying on space-based observatories.

Astron. Astrophys. http://doi.org/n2b (2013)