The electric wind of Venus: A global and persistent 'polar wind'-like ambipolar electric field sufficient for the direct escape of heavy ionospheric ions
| Autor: | Stas Barabash, T. L. Zhang, George V. Khazanov, Glyn Collinson, R. A. Frahm, Andrei Fedorov, Thomas E. Moore, Tom Nordheim, David L. Mitchell, Lin Gilbert, Shawn Domagal-Goldman, Andrew J. Coates, John D. Winningham, W. K. Peterson, Yoshifumi Futaana, Alex Glocer, Joseph M. Grebowsky |
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| Rok vydání: | 2016 |
| Předmět: |
Physics
010504 meteorology & atmospheric sciences Atmospheric escape biology Ambipolar diffusion Astronomy Magnetosphere Venus biology.organism_classification 01 natural sciences Astrobiology Ion wind Solar wind Geophysics Polar wind Planet Physics::Space Physics 0103 physical sciences General Earth and Planetary Sciences Astrophysics::Earth and Planetary Astrophysics 010303 astronomy & astrophysics 0105 earth and related environmental sciences |
| Zdroj: | Geophysical Research Letters. 43:5926-5934 |
| ISSN: | 0094-8276 |
| Popis: | Understanding what processes govern atmospheric escape and the loss of planetary water is of paramount importance for understanding how life in the universe can exist. One mechanism thought to be important at all planets is an “ambipolar” electric field that helps ions overcome gravity. We report the discovery and first quantitative extraterrestrial measurements of such a field at the planet Venus. Unexpectedly, despite comparable gravity, we show the field to be five times stronger than in Earth's similar ionosphere. Contrary to our understanding, Venus would still lose heavy ions (including oxygen and all water-group species) to space, even if there were no stripping by the solar wind. We therefore find that it is possible for planets to lose heavy ions to space entirely through electric forces in their ionospheres and such an “electric wind” must be considered when studying the evolution and potential habitability of any planet in any star system. |
| Databáze: | OpenAIRE |
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