Ganymede (moon) and possibly a JAXA-led Jupiter Magnetospheric Orbiter. ESA's contribution faced funding competition from other ESA projects, but on 2 May 2012 the European part of the mission, renamed Jupiter Icy Moon Explorer (JUICE), obtained a L1 launch slot in 2022 with an Ariane 5 in the ESA's Cosmic Vision science programme. The spacecraft will orbit Ganymede and conduct multiple flyby investigations of Callisto and Europa. The Russian Space Research Institute is currently evaluating the Ganymede Lander (GL) mission, with emphasis on astrobiology. The Ganymede Lander would be a partner mission for JUpiter ICy moon Explorer (JUICE). If selected, it would
Moon to the planet's equatorial plane. The Moon's orbit is subtly perturbed by the Sun and Earth in many small, complex and interacting ways. For example, the plane of the Moon's orbit gradually rotates once every 18.61 years, which affects other aspects of lunar motion. These follow-on effects are mathematically described by Cassini's laws. The Moon is exceptionally large relative to Earth: Its diameter is more than a quarter and its mass is 1/81 of Earth's. It is the largest moon in the Solar System relative to the size of its planet, though Charon is larger relative to the dwarf planet