Overlapping Impact Craters

The surface of Mercury is dominated by impact craters, so it is not surprising that every so often one crater forms atop another. In this image, a small crater formed close to the southern margin of Mercury's northern volcanic plains, before being superposed by a slightly larger and deeper crater. This second impact removed over a third of the smaller, pre-existing crater. Yet both craters show evidence of post-formation modification, notably where their walls meet their floors. For example, a hill lies at the base of the right-hand-side wall of the larger crater. This is likely a landslide deposit that formed when material slumped off the wall.

This image was acquired as a high-resolution targeted observation. Targeted observations are images of a small area on Mercury's surface at resolutions much higher than the 200-meter/pixel morphology base map. It is not possible to cover all of Mercury's surface at this high resolution, but typically several areas of high scientific interest are imaged in this mode each week.

Date acquired: July 10, 2014
Image Mission Elapsed Time (MET): 47351839
Image ID: 6659618
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 52.3°
Center Longitude: 31.6° E
Resolution: 22 meters/pixel
Scale: The crater at center-right is approximately 10 km (6.2 miles) across
Incidence Angle: 54.1°
Emission Angle: 28.3°
Phase Angle: 45.2°
Orientation: North is to the right in this image.

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

Peppered Hills in the Northern Plains

Today's image features several rolling hills within the northern plains of Mercury. Though covered by smooth plains material, these hills are associated with the rim of an unnamed buried crater. At this high resolution, many small craters can be seen dotting the landscape, some as small as ~20-30 m (65-100 ft) in diameter.

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.

Date acquired: April 04, 2014
Image Mission Elapsed Time (MET): 38930993
Image ID: 6061617
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 81.67°
Center Longitude: 234.2° E
Resolution: 16 meters/pixel
Scale: This image is about 9 km (5.6 mi) across.
Incidence Angle: 81.9°
Emission Angle: 21.9°
Phase Angle: 82.3°

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

Hill Near Mercury's Northern Plains

This hill lies towards the edge of Mercury's expansive northern plains. The Sun was low in the sky (high incidence angle) when this image was acquired, resulting in a shadow approximately 3.3 km (2 miles) long. Using trigonometry and knowledge of the incidence angle, the height of the hill can be calculated: ~340 m (~0.2 mile). This hill might be the remnants of an old crater rim that was subsequently flooded. North is to the right of this image.

This image was acquired as a high-resolution targeted observation. Targeted observations are images of a small area on Mercury's surface at resolutions much higher than the 200-meter/pixel morphology base map. It is not possible to cover all of Mercury's surface at this high resolution, but typically several areas of high scientific interest are imaged in this mode each week.

Date acquired: March 25, 2014
Image Mission Elapsed Time (MET): 38066727
Image ID: 6000245
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 83.92°
Center Longitude: 242.3° E
Resolution: 13 meters/pixel
Scale: This image is approximately 7 km (4.3 mi.) across.
Incidence Angle: 84.0°
Emission Angle: 1.9°
Phase Angle: 82.0°

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

Hilly Terrain NW of Angkor Vallis

With the Sun low on the horizon, shadows accentuate the hilly nature of this terrain. This surface has been battered by repeated impacts for billions of years, creating the hilly surface that exists today. As a previous featured image of a nearby area put it, Mercury has been a "planetary punching bag."

This image was acquired as a high-resolution targeted observation. Targeted observations are images of a small area on Mercury's surface at resolutions much higher than the 200-meter/pixel morphology base map. It is not possible to cover all of Mercury's surface at this high resolution, but typically several areas of high scientific interest are imaged in this mode each week.

Date acquired: November 12, 2013
Image Mission Elapsed Time (MET): 26543484
Image ID: 5181047
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 67.11°
Center Longitude: 249.8° E
Resolution: 11 meters/pixel
Scale: This image is 14.6 kilometers (9.1 miles) across
Incidence Angle: 82.0°
Emission Angle: 36.9°
Phase Angle: 118.9°

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

Note: This image is located northwest of Angkor Vallis in the Raditladi Quadrangle.