For an idea of what the weather is like on an exoplanet - a particularly wind one in this case - just look to HD 189733b.
Published in the Astrophysical Journal, the new study detailed the exoplanet's violent winds that can reach up to 5,400 mph. Some 60 light years from Earth, the exoplanet has wind speeds seven times faster than the speed of sound.
"This is the first ever weather map from outside of our solar system. Whilst we have previously known of wind on exoplanets, we have never before been able to directly measure and map a weather system," study co-author Tom Louden, an astrophysicist at the University of Warwick, said in a press release. "HD 189733b's velocity was measured using high resolution spectroscopy of the Sodium absorption featured in its atmosphere. As parts of HD 189733b's atmosphere move towards or away from the Earth the Doppler effect changes the wavelength of this feature, which allows the velocity to be measured.
"The surface of the star is brighter at the centre than it is at the edge, so as the planet moves in front of the star the relative amount of light blocked by different parts of the atmosphere changes. For the first time we've used this information to measure the velocities on opposite sides of the planet independently, which gives us our velocity map."
According to The Washington Post, HD 189733b was a prime target for observation. While it may not fit the bill as an Earth-like planet as well as other exoplanets, it is relatively close to Earth and is huge, about 10 percent larger than Jupiter.
"We are tremendously excited to have found a way to map weather systems on distant planets," study co-author Peter Wheatley, an astrophysicist at Warwick, said in the release. "As we develop the technique further we will be able to study wind flows in increasing detail and make weather maps of smaller planets. Ultimately this technique will allow us to image the weather systems on Earth-like planets."
