Saturday, February 22, 2014
Space scientists located on three continents have published a survey of hot flow anomalies (HFAs) observed at the bow shock of Venus, in Journal of Geophysical Research on Tuesday. HFAs, discontinuities in the solar wind, were found to have much larger repercussions for Venus than for Earth.
While the common HFA space weather phenomenon is deflected by the Earth’s magnetosphere, Venus does not have such a reliable protection against the constant solar wind. Venus’s ionosphere is generally in a sensitive balance with the outside pressure from the solar wind, and is regularly disrupted by the anomalies.
The survey was conducted using data collected during roughly three Venusian days (about two Earth years) by the European Space Agency’s Venus Express, expanding on an initial case study of a HFA at Venus published in 2012. “Not only are they gigantic,” said Glyn Collinson of NASA, the first author of the papers published in 2012 and 2014, “[b]ut 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.” Seven events were observed during the surveyed time.
