Exploration of Jupiter its first Large mission, replacing its contribution to EJSM, the "Jupiter Ganymede Orbiter" (JGO). The partnership for the Europa Jupiter System Mission has since ended, but NASA will continue to contribute the European mission with hardware and an instrument. The "Europa Clipper" is a mission proposed to NASA to focus on studying Jupiter's moon Europa. In March 2013, funds were authorized for "pre-formulation and/or formulation activities for a mission that meets the science goals outlined for the Jupiter Europa mission in the most recent planetary decadal survey". The proposed mission would be set to launch in the early 2020s and
Origin of the Moon colliding body's mass could likely have been part of the Moon. Some theories have been stated that presume the Earth had no large moons early in the formation of the Solar System, 4.6 billion years ago, Earth being basically rock and lava. Theia, an early protoplanet the size of Mars, hit Earth in such a way that it ejected a considerable amount of material away from Earth. Some proportion of this ejecta escaped into space, but the rest consolidated into a single body in orbit about Earth, creating the Moon. The hypothesis requires a collision between a body about 90%