Dynamic Planet: Mercury in the Context of Its Environment

Abstract

Mercury, the Sun's nearest neighbor, is tantalizingly close to the Earth yet is one of the least explored objects in our solar system. The planet's proximity to the Sun makes Earth‐based observations extremely difficult, and the harsh environment presents a significant challenge to spacecraft. Nevertheless, we are currently on the verge of a new era of exploration of this fascinating, mysterious, and largely uncharted world.Much of our knowledge about Mercury has come from just three flybys by NASA's Mariner 10 spacecraft in the mid‐1970s. This mission sent back stunning images of about 45% of the planet's surface and made the truly puzzling discovery of a magnetic field, the source of which is still unknown. Currently, NASA's Mercury Surface, Space Environment, Geochemistry, and Ranging (MESSENGER) mission is beginning to explore Mercury and aims to answer many unresolved questions about the structure, composition, magnetic field, and history of this incredible world. To date, MESSENGER has conducted two flybys and is expected to go into orbit around Mercury in March 2011. Later, in 2013, the European Space Agency's BepiColombo mission, which uses a twin spacecraft approach, will head for the planet to understand the detail of this dynamic system.