Energetic particles fill the universe and can tell us how that universe originated and what it is made of. They shape the way in which our own and other solar systems work, how planets are formed and what the conditions for the emergence and continuation of life might be. The process of particle acceleration itself is found throughout the universe in environments as diverse as stellar coronae, active galactic nuclei, the coronae of accretion disks around black holes, the magnetospheres of neutron stars and planetary atmospheres interacting with the wind of their star.

Despite the critical role of particle acceleration in shaping the universe as we know it, the details of the physical processes themselves poorly understood. The SPARK mission will primarily observe the Sun in order to understand the processes of particle acceleration involved and in particular its extremes. SPARK will make the first space measurements of the far infrared component of solar flares, the first series of gamma-ray line images, and the most sensitive measurements yet of the hard X-ray (HXR) and gamma-ray spectrum, placing us ideally to make significant progress in understanding the roles of electric fields, shocks and wave-particle interactions in accelerating particles on the Sun.