The gamma-ray emission from the Earth atmosphere, on one hand, appears as a rather steady emission generated either by reflection of the Cosmic X-ray Background on the atmosphere or by the interaction of cosmic-rays on atmospheric atoms. It has been observed by the ESA gamma-ray mission INTEGRAL and will be studied in the next future by the IGOSAT project. Indeed, IGOSAT (Ionosphere and Gamma-ray Observations Satellite) is a nanosatellite project, to be launched in 2022,  aimed to measure the gamma-ray and electrons radiation in low Earth orbit.

We can observe also luminous fast gamma-ray events, called Terrestrial Gamma-ray Flashes (TGF), which are observed on Earth and in space; they are produced by lightning during thunderstorms. These events will be observed in much details by the TARANIS mission, a microsatellite from CNES to be launched next year. TARANIS aims to observe TGF and their accompanied optical Transient Luminous Events (TLE) over  the whole electromagnetic band from radio, optical to gamma-rays.

In my talk, I will describe these different phenomena and their past and future observations we will perform with INTEGRAL, IGOSAT and TARANIS."