solar-wind-theta

NASA’s missions reveal the origin of theta auroras

Auroras are the most visible manifestation of the sun’s effect on Earth, but many aspects of these spectacular displays are still poorly understood. Thanks to the joint European Space Agency and NASA’s Cluster mission combined with data from a past NASA mission called the Imager for Magnetopause-to-Aurora Global Exploration, or IMAGE, a particular type of…

birkel;and_currents_sun

Observing the Birkeland currents borne of the solar wind

  When the supersonic solar wind hits the Earth’s magnetic field, a powerful electrical connection occurs with Earth’s field, generating millions of amperes of current that drive the dazzling auroras. These so-called Birkeland currents connect the ionosphere to the magnetosphere and channel solar wind energy to Earth’s uppermost atmosphere. Solar storms release torrential blasts of solar…