Barring winds associated with tornados, the strongest wind gust recorded occurred on April 10, 1996 at Barrow Island, Australia. According to the World Meteorological Association, the record shattering wind gust was a result of Cyclone Olivia. The speed was 408 km/h, or around 253 mph.
But beyond Earth, beyond the reaches of the solar system, an exoplanet is ravaged by winds seven times the speed of sound.
“Whilst we have previously known of wind on exoplanets, we have never before been able to directly measure and map a weather system,” said Tom Louden, of the university’s astrophysics group.
Part of a group called “Hot Jupiters,” HD 189733b is 10% larger than Jupiter but 180 times closer to its host star. Its surface temperature is 1,200 C.
Using the High Accuracy Radial velocity Planet Searcher in Chile, Univ. of Warwick researchers collected data that allowed them to measure and map the exoplanet’s weather system. By measuring the velocities of the exoplanet’s two sides, the researchers discovered a strong wind traveling at 5,400 mph from its dayside to its night side.
“HD 189733b’s velocity was measured using high resolution spectroscopy of the sodium absorption featured in its atmosphere,” said Louden. “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 center 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,” he continued. “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 researchers, the technique used may help scientists further study Earth-like planets.
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