By re-creating the conditions for an aurora in the lab, researchers have confirmed how these bright, shimmery curtains of light form.
The northern lights arise when electrons from space cascade into the upper atmosphere, where they collide with oxygen and nitrogen molecules to paint the sky red and green (SN: 2/7/20). But it has been difficult to discern what, exactly, draws those electrons down toward Earth. For decades, scientists have suspected that electrons ride ripples in Earth’s magnetic field, called Alfvén waves, into the atmosphere, like tiny surfers catching waves to shore. But no satellite has ever directly observed this happening.
A new experiment that accelerated electrons with Alfvén
→ Continue reading at Science News