Image: NASA, JHU/APL, CIW

On 29 September, the MESSENGER spacecraft will fly by Mercury for the third and final time, a maneuver that will be key to placing the probe on a trajectory that will enable its March 2011 insertion into the orbit about Mercury. The spacecraft will pass 228 km (142 miles) above Mercury’s surface.

With more than 90 percent of the planet’s surface already imaged, the team will turn its instruments toward specific targets during this flyby. The probe will again image the planet, including a small amount of never-before-seen surface, but the cameras will be trained in particular on interesting areas identified from the second flyby for more detailed spectral measurements. For information on the third flyby, see the MESSENGER Web site.