As MESSENGER flew by the planet, it missed its targeted aim point by only 8.25 kilometers (5.12 miles), affording the critical gravity assist needed to continue on a course to become – in 2011 – the first spacecraft ever to orbit Mercury. In addition to images of the previously unseen portion of the planet’s surface, measurements were made that will contribute to the characterization of all aspects of Mercury and its environment, from its metallic core to the far reaches of its magnetosphere.