Universe Today
NASA's THEMIS mission was blasted into space on Saturday, February 17 atop a Delta II rocket. THEMIS stands for Time History of Events and Macroscale Interactions during Substorms, and it's comprised of 5 separate spacecraft.
Each of the 128-kg (282-pound) spacecraft is equipped with identical instrumentation. They will fly in different positions between the Earth and the Sun to help measure the interaction between the solar wind and the Earth's magnetosphere. Some of the energy created by this interaction causes magnetic field lines to stretch and snap like rubber bands. We see the snaps as beautiful auroral displays.
The spacecraft are currently making their way to their final science orbits, which they should reach in mid-September.
NASA News Release
