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
History of Mars observation Earth in an orbit around the Sun between the circular orbits of Venus and Mars. His model successfully explained why the planets Mars, Jupiter and Saturn were on the opposite side of the sky from the Sun whenever they were in the middle of their retrograde motions. Copernicus was able to sort the planets into their correct heliocentric order based solely on the period of their orbits about the Sun. His theory gradually gained acceptance among European astronomers, particularly after the publication of the "Prutenic Tables" by the German astronomer Erasmus Reinhold in 1551, which were computed using the Copernican