INTEGRAL serendipitous observations of solar and terrestrial X-rays and gamma rays

ESA's INTEGRAL space mission has achieved unique results for solar and terrestrial physics, although spacecraft operations nominally excluded the possibility to point at Sun or Earth. The Earth avoidance was, however, exceptionally relaxed special occultation observations of Cosmic X-ray Background (CXB), which on some occasions allowed detection strong auroral emission. In addition, most intense flares can be bright enough detectable from outside field view main instruments. This article presents first time by reviews earlier studies flares. We end briefly summarising Earth's radiation belts, considered as another topic serendipitous science with INTEGRAL.