The interaction between the solar wind and the Earth’s magneto - sphere results in “space weather.” To determine the true nature of the solar wind-magnetosphere interaction, scientists require global measurements of processes occurring at the bow shock, in the magnetosheath, and at the magnetopause. Such observations can only be obtained from imaging this interaction globally. This will produce a paradigm shift similar to how satellite imaging revolutionized terrestrial weather forecasting.
Charge exchange between solar wind ions and cold neutral gas results in soft X-ray emission, a process that occurs everywhere the solar wind coexists with neutral gas: at comets, in the interplanetary medium, at Venus, at Mars, at Earth’s moon, and at Earth itself. These soft x-rays are always observed at some level by narrow field-of-view astrophysical telescopes making observations of distant objects and, in many cases, constitute a significant source of background.
On December 12, 2012, Goddard scientists successfully flew the first wide field-of-view soft X-ray imager tailored for studying this process on a Black Brant sounding rocket. The imager, STORM (Sheath Transport Observer for the Redistribution of Mass), flew as a secondary payload on the DXL (Diffuse X-ray emission from the Local galaxy) mission, on which the Goddard scientists are co-investigators. While STORM images charge exchange close to Earth, DXL observed interplanetary charge exchange from the helium focusing cone. The DXL results proved the existence of the Local Hot Bubble. The result was featured on NASA’s Science News: http://science.nasa.gov/sciencenews/science-at-nasa/2014/26aug_localbubble/ .
The Goddard prototype wide field-of-view (FOV) soft x-ray imager employs University of Leicester/Photonis-developed micropore reflectors to focus soft X-rays onto a position-sensing micro-channel plate detector plane. The Goddard team flew the STORM imager to demonstrate its functionality and raise its TRL (technology readiness level) to 7. In the process, the team established that the STORM design is even more rugged than expected — it survived a much rougher rocket flight than anticipated. Post-flight analysis of STORM observations of the soft X-ray background demonstrated that the STORM has the required sensitivity and spatial resolution to track soft X-ray emitting magneto - sheath and magnetopause features.
This work was done by Michael Collier, Frederick Porter, and David Sibeck of Goddard Space Flight Center. GSC-16957-1