A common space weather phenomenon that takes place on the outskirts of Earth’s magnetic bubble has a major effect for Venus.
Known as hot flow anomalies, release a large amount of energy outside the magnetosphere that solar wind deflects. But Venus does not have a magnetic bubble making its reaction to the same event quite different – and possibly life-threatening for the terrestrial planet.
"Not only are they gigantic," Glyn Collinson, a space scientist at NASA's Goddard Space Flight Center in Greenbelt, Md., said in a statement. "But as Venus doesn't have a magnetic field to protect itself, the hot flow anomalies happen right on top of the planet. They could swallow the planet whole."
The findings, published in the Journal of Geophysical Research, were drawn from observations taken at the European Space Agency's Venus Express where the weather phenomenon was captured frequently.
Scientists compared how hot flow anomalies affected the two planets. While Earth has a magnetosphere and solar wind that can deflect the energy towards the sun, Venus’ only form of protection is an outer layer called an ionosphere. There is a sensitive balance between solar wind and the ionosphere. If a hot flow anomaly disrupts the balance, it could cause a planet-sized explosion that can suck the ionosphere up and away from the Venus’ surface.
Venus Express, a satellite that has been orbiting Venus since April 2006, collects information on the planet’s atmosphere, plasma environment, and surface. In January, images from the mission showed the planet is blanketed in high-level clouds known as gravity waves.
"We believe that these waves are at least partly associated with atmospheric flow over Ishtar Terra, an upland region which includes the highest mountains on Venus," Silvia Tellmann from the University of Cologne, Germany, said at the time. "We don't yet fully understand how such topographic forcing can extend to high levels, but it seems likely to be one of the key processes for the generation of gravity waves at high northern latitudes on Venus. The waves may form when a stable air flow passes over the mountains."