Secondary Craters in the Northern Plains

This image is one of the highest resolution images taken by the MESSENGER spacecraft to date. It features a field of secondary craters in Mercury's northern smooth plains. Secondary craters are formed by the re-impact of debris strewn from a larger crater. The largest secondary craters in this image are roughly a few hundred meters across. If you look closely, you can see some small craters that are only tens of meters across. All of these craters are simple craters.

This image was acquired as part of the MDIS low-altitude imaging campaign. During MESSENGER's second extended mission, the spacecraft makes a progressively closer approach to Mercury's surface than at any previous point in the mission, enabling the acquisition of high-spatial-resolution data. For spacecraft altitudes below 350 kilometers, NAC images are acquired with pixel scales ranging from 20 meters to as little as 2 meters.

On 25 July 2014, MESSENGER moved closer to Mercury than any spacecraft has before, dropping to an altitude of 100 kilometers (60 miles) above the planet's surface. By 19 August 2014, the minimum altitude will be cut in half, to only 50 kilometers (31 miles)! MESSENGER will execute three more orbit-correction maneuvers in order to delay the end of mission to late March 2015. For more details on this event, read this news story.

Date acquired: June 11, 2014
Image Mission Elapsed Time (MET): 44779109
Image ID: 6477542
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 69.84°
Center Longitude: 48.47° E
Resolution: 2.9 meters/pixel
Scale: This image is about 3 km (1.8 miles) across.
Incidence Angle: 79.4°
Emission Angle: 0.1°
Phase Angle: 79.6°

Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington