Tidal waves of lava may slosh around alien worlds

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By Elise Cutts, Science. 

Excerpt: Towering tidal waves of lava could be rolling around hot alien worlds, researchers reported last week, here at the Rocky Worlds conference and in a preprint posted on arXiv this month. The Sun and Moon drive tides on Earth, but these tidal waves would be tugged up by the intense gravitational forces endured by planets in tight orbits around their stars. For instance, lava tidal waves on the blazing-hot exoplanet 55 Cancri e—a rocky world that orbits its star every 18 hours—could rise several hundred meters high and surge at the speed of a human sprinter, says Mohammad Farhat, a planetary scientist at the University of California (UC), Berkeley who presented the modeling study. ...Scientists often look for alien air by taking the temperatures of planets’ dayside hemispheres. The presence of an atmosphere would spread heat around to the nightside, making the dayside look cooler than expected for a bare rock. But if lava waves can melt deep magma oceans and create wandering blobs of hot material, it raises questions about whether it would mimic the observational signal of an atmosphere.... 

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