NASA Spacecraft Uncover Mystery Behind Auroral Beads
Released on August 14, 2020
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. Until now, 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 direct evidence of the events in space that lead to the appearance of these beads, and demonstrated the important role they play in our local space environment.
The photograph was taken east of Saskatoon on winter solstice in 2015 with a 81% illuminated waxing gibbous Moon. It was processed with PixInsight to remove streaks caused due to an accidentally nudged tripod during exposure while attempting to retain realistic star shapes and colors. The exposure time was 2.5 seconds.
External influence on geomagnetic field, shown in red (strengthened) – white (unaffected) – grey (weakened), in the equatorial plane of the magnetosphere. The formation of buoyant bubbles can be seen on the night side of Earth (left) shortly after the change in the orientation of the solar wind magnetic field at T=0.
Credit: Kareem Sorathia (JHUAPL/Center for Geospace Storms)
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 184.108.40.206.0