Io's molten ocean - Data analysis from NASA's Galileo spacecraft reveals a subsurface ocean of molten or partially molten magma beneath the surface of Jupiter's volcanic moon Io. The finding heralds the first direct confirmation of this kind of magma layer at Io and explains why the moon is the most volcanic object known in the solar system.

The surprisingly low geotherm under which 4.2 billion-year-old zircons formed, together with inclusion assemblages characteristic of subduction-related magmas, indicates their formation in a convergent margin environment. This implies that plate tectonics initiated on Earth almost immediately following planetary formation.

Spacecraft images show ‘spirals on the sea’ in sunlight and radar reflectance but none have been measured in situ. In oceanic simulations with high spatial resolution, spiral structures have been shown to emerge from the instability and wrap-up of cold surface temperature filaments undergoing frontogenetic collapse induced by surrounding mesoscale eddy currents.

Snapshots of increasing atmospheric vorticity at one altitude resulting from incrementally decreasing the spin rate of an Earth-like planet. The transition to superrotation – where the atmosphere spins faster than the surface – occurs at figure 4.

Regional and global climate models identify several regions as prone to increased drought conditions. This image shows predictions for the Caribbean and Central America which indicte reduced rainfall under global warming. Implications for extreme weather (e.g. hurricanes) are being investigated.

ARTEMIS: two tiny spacecraft that could reach for the moon. Two THEMIS microsatellites previously orbiting Earth are being repositioned to orbit the moon. They constitute ARTEMIS, the first mission to study the lunar wake, exosphere and radiation environment from two vantage points, resolving space-time ambiguities.

THEMIS, a NASA five spacecraft mission, discovers that magnetic reconnection, powered by the Sun's expanding corona when it interacts with Earth's space environment, releases the particle and electromagnetic radiation that ignite spectacular polar auroral displays, resolving a 40 year old mystery.

Ganymede is the only moon known to have a magnetosphere. Shown in this figure are magnetic field lines (green) from a recent magnetohydrodynamic simulation to the interaction of Jovian plasma with Ganymede. The red regions show currents on the magnetopause of Ganymede and in the magnetotail.