Jupiter Magnetospheric Orbiter the orbiter was proposed for a lift-off in 2020 together with ESA's Jupiter Ganymede Orbiter (JGO) from which it would undock upon its arrival at Jupiter in 2025/2026. However, the EJSM collaboration was disbanded and NASA renamed its initiative with Europa Multiple-Flyby Mission, ESA's Jupiter Icy Moon Explorer, and Roscosmos's Laplace-P. The JMO objective was to undertake detailed "in situ" studies of the magnetosphere of Jupiter as a template for an astrophysical magnetised disk for "3-point" investigations of the Jupiter system via synergistic observations with other orbiters. The size and weight of the JMO would have been limited to carry
Atmosphere of Mars atmosphere is thinnest." Spectroscopic observations in the 1860s and 1870s led many to think the atmosphere of Mars is similar to Earth's. In 1894, though, spectral analysis and other qualitative observations by William Wallace Campbell suggested Mars resembles the Moon, which has no appreciable atmosphere, in many respects. In 1926, photographic observations by William Hammond Wright at the Lick Observatory allowed Donald Howard Menzel to discover quantitative evidence of Mars's atmosphere. The main component of the atmosphere of Mars is carbon dioxide () at 95.9%. Each pole is in continual darkness during its hemisphere's winter, and the surface gets so