A faint electric field has been detected in Earth’s atmosphere, confirming a theory that scientists have held for decades. This ambipolar electric field, though weak at just 0.55 volts, could play a vital role in shaping Earth’s atmospheric evolution and its ability to support life, according to recent findings. Glyn Collinson, an atmospheric scientist at NASA’s Goddard Space Flight Center, led the Endurance rocket mission, which successfully measured this field in May 2022 above Svalbard, Norway. Collinson has described this field as a “planetary-energy field” that had eluded scientific measurement until now.
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How the Ambipolar Field Affects Earth’s Atmosphere
The presence of this field is thought to explain a phenomenon observed decades ago—the polar wind. When sunlight strikes atoms in the upper atmosphere, it can cause negatively charged electrons to break free and drift into space, while the heavier, positively charged oxygen ions remain. To maintain an electrically neutral atmosphere, a faint electric field forms, tying these particles together and preventing electrons from escaping. This weak field has been shown to provide energy to lighter ions, such as hydrogen, enabling them to break free from Earth’s gravity and contribute to the polar wind.
This ambipolar electric field could have implications for planetary habitability. David Brain, a planetary scientist at the University of Colorado Boulder, noted that understanding how such fields vary across planets could shed light on why Earth has remained habitable compared to planets like Mars and Venus. Although both Mars and Venus have electric fields, the absence of a global magnetic field on those planets allowed more of their atmospheres to escape into space, potentially altering their climates significantly.
Further Research Planned
NASA has recently approved a follow-up mission with a rocket named Resolute, expected to launch soon. Collinson believes that continued investigation into planetary electric fields may help answer fundamental questions about why Earth supports life while other planets do not.
