Earth against the cosmic X-ray background

This preliminary gamma-ray image has been taken by the SPI spectrometer on board Integral, during the Earth observation campaign (January-February 2006). The dark central part represents the Earth disc (about 5-7 degrees in diameter) transiting in the instrument's field of view (2.5 deg), that explains the blurred Earth rim in the image. The cosmic X-ray background radiation in the vicinity of Earth is characterised by a strong emission of high-energy (hard) X-rays.