Explosions on Venus engulf entire planet

A common space weather phenomenon on the outskirts of Earth's magnetic bubble has larger -- much larger -- repercussions for Venus, NASA scientists say.

Giant explosions called hot flow anomalies in the solar wind can be so large when they encounter Venus they're bigger than the entire planet can happen multiple times a day, they said.

"Not only are they gigantic," Glyn Collinson, a space scientist at NASA's Goddard Space Flight Center in Greenbelt, Md., said, "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."

Collinson is the lead author of a paper based on observations from the European Space Agency's Venus Express, showing just how large and how frequent this kind of space weather is at Venus.

Earth is protected from the constant streaming solar wind of radiation by its magnetic bubble -- the magnetosphere -- while Venus, a barren, inhospitable planet with an atmosphere so dense spacecraft landing there are crushed within hours, Venus has no such magnetic protection.

At Earth, hot flow anomalies do not make it inside the magnetosphere, whereas on Venus they can create dramatic planet-scale disruptions, possibly sucking the planet's upper atmosphere up and away from the surface, the scientists said.

That suggests Earth without its magnetic field might be as barren and lifeless as Venus, they said.