Adrastea

Adrastea was illuminated through images captured by the Voyager 2 spacecraft during its momentous flyby of Jupiter. Learn all about Adrastea here!

Physical Characteristics

Standing as one of the smallest moons in Jupiter's cosmic retinue, Adrastea boasts a modest diameter of approximately 20 kilometers (equivalent to 12 miles). Its shape veers away from the conventional roundness, with its irregular form suggesting a history rife with asteroid impacts that have carved its surface over eons.

Orbit

Adrastea's orbit is remarkably close to its planetary parent, Jupiter. At an average distance of about 129,000 kilometers (roughly 80,000 miles) from the center of the gas giant, Adrastea treads within the fringes of Jupiter's Main Ring, contributing to the dynamic tapestry of its orbital neighborhood. The moon's orbit takes it through the particles composing Jupiter's Main Ring, and its gravitational influence significantly contributes to the structure and stability of the ring system. Adrastea's presence gives rise to a phenomenon known as "shepherding," wherein its gravitational pull confines the ring particles to specific regions, helping maintain the integrity of the ring edges.

Surface Features

Owing to its relatively petite dimensions and the consequent subdued gravitational forces, Adrastea's terrain is likely riddled with the telltale marks of asteroid impacts—craters etched upon its surface. The moon's intimate proximity to Jupiter exposes it to significant tidal forces, which might also result in surface features such as fractures and fissures, shaped by the gravitational interplay between Adrastea and its colossal host planet.