Flying within 228 kilometers of the surface of Mercury on Sept. 29, the Messenger spacecraft snapped portraits of a portion of the planet that had never before been imaged close up.

Messenger also examined in greater detail Mercury’s western hemisphere, which had been imaged during a previous passage in October 2008 (SN Online: 10/29/08).

The Sept. 29 encounter was the third and last flyby and gave the craft the gravitational assistance it needs to settle in March 2011 into a yearlong orbit around Mercury, the solar system’s innermost and least explored planet. The first images from the latest encounter, which detail 5 percent of the planet that hadn’t been examined by spacecraft before, were released on Sept. 30 and more are expected over the next few days.

*Images: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of WashingtonSee Also: