Hair standing on end during a thunderstorm is a bad sign. It means lightning is on its way. On one faraway planet, though, static hair might be the least of your worries.
The planet is HAT-P-11b. It is an exoplanet — a planet far outside Earth’s solar system — some 124 light-years away. Scientists detected a surge of radio waves from the planet several years ago. Those waves could be caused by a barrage of lightning striking 530 times as often per square kilometer (0.4 square mile) as storms do in the United States.
This is the conclusion of Gabriella Hodosán of the University of St. Andrews in Scotland and her colleagues. They reported their finding April 23 in Monthly Notices of the Royal Astronomical Society.
In 2009, astronomers recorded radio waves coming from the HAT-P-11 system. The radio waves ceased when the planet slipped behind its star. That suggested the planet was the source of the signal. A second look in 2010 found no radio waves.
Scientists have detected lightning on planets closer to home, including Venus and Jupiter. But they have never before found lightning on a planet orbiting a star other than the sun.
HAT-P-11b is too close to its star for astronomers to see visible flashes of light. But an infrared telescope might pick up a stockpile of hydrogen cyanide created by such electrical discharges.