To uncover the mysteries behind the formation of auroral beads, scientists combined measurements from NASA's THEMIS mission and ground observations with computer models.
Credits: NASA's Goddard Space Flight Center
A special type of aurora, draped east-west across the night sky like a glowing pearl necklace, is helping scientists better understand the science of auroras and their powerful drivers out in space. Known as auroral beads, these lights often show up just before large auroral displays, which are caused by electrical storms in space called substorms. Previously, scientists weren’t sure if auroral beads are somehow connected to other auroral displays as a phenomenon in space that precedes substorms, or if they are caused by disturbances closer to Earth’s atmosphere.
But powerful new computer models combined with observations from NASA’s Time History of Events and Macroscale Interactions during Substorms – THEMIS – mission have provided the first strong evidence of the events in space that lead to the appearance of these beads, and demonstrated the important role they play in our near space environment.
“Now we know for certain that the formation of these beads is part of a process that precedes the triggering of a substorm in space,” said Vassilis Angelopoulos, principal investigator of THEMIS at the University of California, Los Angeles. “This is an important new piece of the puzzle.”
Watch video: https://www.youtube.com/watch?v=fwE02OBWoKQ