A recent study, appearing online in the Journal of Geophysical Research on February 29, 2012, has found clear evidence on Venus for a type of space weather outburst quite common at Earth, called a hot flow anomaly. These anomalies, also known as HFAs, cause a temporary reversal of the solar wind that normally moves past a planet. An HFA surge causes the material to flood backward, says David Sibeck, a scientist at NASA’s Goddard Space Flight Center in Greenbelt, Md., who studies HFAs at Earth and is a co-author on the paper.
“They are an amazing phenomenon,” says Sibeck. “Hot flow anomalies release so much energy that the solar wind is deflected, and can even move back toward the sun. That’s a lot of energy when you consider that the solar wind is supersonic — traveling faster than the speed of sound — and the HFA is strong enough to make it turn around.”
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