23:33 UT, 26 July 1986
This image was taken by an Xray pinhole camera, flown on a stratospheric balloon from Kiruna, Sweden in July, 1986. The area of the sky shown is approximately 100 km across, and was taken during a period of intense visual aurora, near local midnight. The bright area in the southwest corner of the image measures ~20 km across, and moved in a matter of minutes across the field of view of the camera. A movie of this event is shown in the second abstract, below. Another movie, showing dayside auroral Xrays, is shown in the third abstract.