Saturday, August 27, 2011

A View Towards the Plains


This view was captured as MDIS pointed to the east, which is oriented as the top of this image. Smooth plains extend into the distance, while the closer ground near the bottom of the image is more heavily cratered and hence rougher in texture. This location is on the edge of volcanic smooth plains that covers a great extent of Mercury's northern region.

Date acquired: August 12, 2011
Image Mission Elapsed Time (MET): 221626724
Image ID: 622112
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: 62.40°
Center Longitude: 321.6° E
Resolution: 242 meters/pixel
Scale: The bottom of this image is 220 kilometers (140 miles) across
Incidence Angle: 82.5°
Emission Angle: 59.4°
Phase Angle: 142.0°

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

Friday, August 26, 2011

Double Ring Impact Basin


This image shows a double ring impact basin with a smaller, younger crater superimposed on its rim. Larger impacts, such as the one that created this basin, form ring structures instead of central peaks.

Date acquired: June 02, 2011
Image Mission Elapsed Time (MET): 215511113
Image ID: 329264
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: -80.35°
Center Longitude: 212.0° E
Resolution: 255 meters/pixel
Scale: The large impact crater is ~165 km (102 mi) in diameter.
Incidence Angle: 81.6°
Emission Angle: 0.9°
Phase Angle: 82.2°

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

Thursday, August 25, 2011

Debussy Crater Rays and a Cosmic Ray


The rays apparent in this spectacular limb image of Mercury come from Debussy, the sharp crater near the terminator. This dominant crater on Mercury was also a part of MESSENGER's historic image of Mercury - the first image ever to be taken from a spacecraft in orbit about this planet. Readers may also notice a streak in the blackness of space in the top right corner of the image. This artifact was produced by a cosmic ray hitting the camera's CCD detector while the image was being collected.

Date acquired: July 26, 2011
Image Mission Elapsed Time (MET): 220137668
Image ID: 550504
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: -27.90°
Center Longitude: 29.17° E
Resolution: 2783 meters/pixel
Scale: Mercury's radius is approximately 2440 km (1516 miles)
Incidence Angle: 65.1°
Emission Angle: 48.2°
Phase Angle: 95.3°

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

Wednesday, August 24, 2011

Ts'ai Wen-Chi Crater and the Long Scarp


A long scarp runs vertically through the center of this image, deforming pre-existing craters along its length. At the bottom of this image, the scarp cuts through the wall and floor of the crater Ts'ai Wen-Chi (124 km diameter), named for the Han Dynasty poet and composer.

Date acquired: August 04, 2011
Image Mission Elapsed Time (MET): 220977824
Image ID: 591397
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: 27.73°
Center Longitude: 337.4° E
Resolution: 432 meters/pixel
Scale: This image is approximately 600 km (370 miles) across
Incidence Angle: 81.9°
Emission Angle: 38.2°
Phase Angle: 120.2°

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

Monday, August 22, 2011

Uncharted Territory


This image, captured by the Narrow Angle Camera (NAC), shows a crater in a region of Mercury not seen by Mariner 10. This crater was first imaged during MESSENGER's Mercury flybys, but this is the first image to reveal its detailed morphology. The crater's name will be chosen in accordance with a set of rules established by the International Astronomical Union (available here). Craters on Mercury are named after deceased artists, musicians, painters or authors who have made outstanding contributions to their fields and who have been considered a historically significant figure for at least 50 years.

Date acquired: July 20, 2011
Image Mission Elapsed Time (MET): 219646866
Image ID: 527953
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 6.70°
Center Longitude: 38.52° E
Resolution: 193 meters/pixel
Scale: This crater is about 113 km (70 miles) in diameter
Incidence Angle: 71.4°
Emission Angle: 15.1°
Phase Angle: 56.2°

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

Sunday, August 21, 2011

Double Trouble


This image, taken by the Narrow Angle Camera (NAC), shows the double rings of an unnamed peak-ring basin. Concentric ring structures like these form during the impact that creates a basin; the number and characteristics of the rings depend on the size of the impact structure and the gravity of the planet.

Date acquired: July 20, 2011
Image Mission Elapsed Time (MET): 219644470
Image ID: 527930
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: -17.66°
Center Longitude: 45.56° E
Resolution: 175 meters/pixel
Scale: The large double ring basin is about 172 km (107 miles) in diameter.
Incidence Angle: 65.6°
Emission Angle: 0.7°
Phase Angle: 66.1°

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

Saturday, August 20, 2011

Happy Trails


This view, captured by the Wide Angle Camera (WAC), shows a trail of small craters. Such secondary crater chains are formed when the ejecta from a primary impact fall in the surrounding area, forming their own often overlapping small craters. Also visible in this image are smooth plains, formed by volcanism that has filled in a large impact crater.

Date acquired: July 15, 2011
Image Mission Elapsed Time (MET): 219181924
Image ID: 505807
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: 83.21°
Center Longitude: 173.6° E
Resolution: 155 meters/pixel
Scale: The small crater at the bottom of the image has a diameter of 24 km (15 miles).
Incidence Angle: 85.3°
Emission Angle: 0.2°
Phase Angle: 85.3°

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

Friday, August 19, 2011

Crater Captivation


This image, captured by the Narrow Angle Camera (NAC), shows an unnamed complex crater in Mercury's southern hemisphere. The smooth crater floor is likely due to impact melt that formed during the collision that produced the crater. Also visible are the peak ring and terraced walls, as well as the ejecta blanket and a large field of secondary craters and crater chains.

Date acquired: July 25, 2011
Image Mission Elapsed Time (MET): 220043917
Image ID: 546489
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: -66.40°
Center Longitude: 81.43° E
Resolution: 326 meters/pixel
Scale: The large crater has a diameter of about 155 km (96 miles)
Incidence Angle: 67.0°
Emission Angle: 33.5°
Phase Angle: 100.5°

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

Thursday, August 18, 2011

Rembrandt Revisited


This limb image shows Rembrandt, the second largest impact basin on Mercury after Caloris. Discovered during the second MESSENGER flyby, Rembrandt is one of the youngest impact basins on Mercury, as indicated by the relatively low density of impact craters on its rim. A large lobate scarp trending from the southwest to the north crosscuts Rembrandt and several of the smaller craters that have impacted the smooth interior plains.

Date acquired: August 07, 2011
Image Mission Elapsed Time (MET): 221198580
Image ID: 601688
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: -32.95°
Center Longitude: 84.90° E
Resolution: 1756 meters/pixel
Scale: The large impact basin is ~715 km (444 mi) in diameter.
Incidence Angle: 46.3°
Emission Angle: 48.7°
Phase Angle: 95.0°

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

Wednesday, August 17, 2011

Impact Crater on the Edge of Oskison Crater


This image features a crater situated at the edge of the larger Oskison crater located in the plains north of Caloris basin. Due to MESSENGER's highly elliptical orbit, MDIS's Wide Angle Camera is capable of capturing higher resolution images in Mercury's northern hemisphere, such as this 58 meters per pixel view. A detailed look at the crater reveals its terraced walls, smooth floor, and its superposition on Oskison's shadowed rim.

Date acquired: August 01, 2011
Image Mission Elapsed Time (MET): 220677117
Image ID: 577219
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: 60.18°
Center Longitude: 141.9° E
Resolution: 58 meters/pixel
Scale: This crater is approximately 39 km (24 mi) in diameter.
Incidence Angle: 81.2°
Emission Angle: 0.8°
Phase Angle: 80.5°

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

Monday, August 8, 2011

Firdousi Crater and Region


This image shows a portion of Mercury's surface mainly consisting of smooth plains material. This lighter, smoother area of plains is younger than the darker, rougher surrounding terrain near the edges of this image. Firdousi crater and its halo of small secondary craters is also apparent in this image, in the lower left quadrant.

Date acquired: July 17, 2011
Image Mission Elapsed Time (MET): 219349510, 219349512, 219349518
Image ID: 513659, 513658, 513662
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 9 (1000 nanometers), 7 (750 nanometers), 6 (433 nanometers) as red-green-blue
Center Latitude: 6.77°
Center Longitude: 69.01° E
Resolution: 1330 meters/pixel
Scale: The large crater in the lower left quadrant of this image is about 134 kilometers (80 miles) in diameter
Incidence Angle: 52.4°
Emission Angle: 0.3°
Phase Angle: 52.4°

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

Sunday, August 7, 2011

Mercury's Smile


This image taken by MDIS's Wide Angle Camera is dominated by an unnamed basin formed from a large impact on the surface of Mercury. Although the impact was energetic enough to create a central peak ring in the basin, the ring has been mostly flooded by impact melt and/or volcanic plains. To the MESSENGER summer interns, the partial ring of mountains resembles a smile.

Date acquired: July 16, 2011
Image Mission Elapsed Time (MET): 219266241
Image ID: 509587
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: 51.79°
Center Longitude: 82.82° E
Resolution: 203 meters/pixel
Scale: The basin is approximately 180 km (112 mi) in diameter
Incidence Angle: 62.3°
Emission Angle: 0.2°
Phase Angle: 62.5°

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

Saturday, August 6, 2011

Matryoshka Dolls


The largest crater in this image is superimposed by three different craters that each have central peaks. The largest of these superimposed craters is overlapped by one of the others, creating a small crater partially inside another which in turn has another smaller crater partially inside it. Much of Mercury's surface is heavily cratered so overlapping craters can be seen in many places, including the areas around Camoes crater seen here.

Date acquired: July 13, 2011
Image Mission Elapsed Time (MET): 219038585
Image ID: 499240
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: -53.88°
Center Longitude: 83.80° E
Resolution: 361 meters/pixel
Scale: The largest crater in this image is approximately 105 km (65.24 mi) wide
Incidence Angle: 67.1°
Emission Angle: 2.0°
Phase Angle: 68.9°

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

Friday, August 5, 2011

Mercury's Surface Variety


This area, previously unseen during the Mariner 10 and MESSENGER flybys, was captured by MESSENGER's Narrow Angle Camera (NAC) in orbit. The view presents both contrasting albedo materials as well as contrasting terrain types. The image includes smooth plains along the left edge and a more rugged surface to the right. A 23-km-diameter impact crater sits between exposures of low reflectance material (LRM) to the east and patches of high albedo material to its west.

Date acquired: July 13, 2011
Image Mission Elapsed Time (MET): 219009759
Image ID: 497191
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 8.93°
Center Longitude: 91.56° E
Resolution: 180 meters/pixel
Scale: The large crater in this image is approximately 23 km (14 mi) in diameter.
Incidence Angle: 42.8°
Emission Angle: 3.0°
Phase Angle: 39.8°

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

Thursday, August 4, 2011

A Saucerful of Secrets


The crater with the central peaks in the northeast portion of this image is located on the eastern rim of a large impact basin. Extending westward from this crater is a wrinkle ridge that may have formed due to contraction as lava that flooded the basin cooled. Scientists studying craters and large impact basins on Mercury learn more and more of the innermost planet's "secrets" as new imagery and data from MESSENGER become available.

This image was acquired as part of MDIS's high-resolution surface morphology base map. The surface morphology base map will cover more than 90% of Mercury's surface with an average resolution of 250 meters/pixel (0.16 miles/pixel or 820 feet/pixel). Images acquired for the surface morphology base map typically have off-vertical Sun angles (i.e., high incidence angles) and visible shadows so as to reveal clearly the topographic form of geologic features.

Date acquired: July 13, 2011
Image Mission Elapsed Time (MET): 219011692
Image ID: 497387
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: 69.75°
Center Longitude: 110.8° E
Resolution: 248 meters/pixel
Scale: Image diagonal is ~180 km (112 mi)
Incidence Angle: 71.3°
Emission Angle: 0.2°
Phase Angle: 71.4°

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

Wednesday, August 3, 2011

The Rays of Qi Bashi Crater


This image, taken by MESSENGER's Narrow Angle Camera, captures Qi Bashi, the brightest crater at the right edge of the view. The brilliant ejecta rays of Qi Bashi extend mostly to the north and south, instead of in all directions. When an impact crater is formed, bright, fresh material is ejected out of the crater into the surrounding area; however, the asymmetrical ejecta as seen here necessitates an extremely low impact angle.

This image was acquired as part of MDIS's high-resolution surface morphology base map. The surface morphology base map will cover more than 90% of Mercury's surface with an average resolution of 250 meters/pixel (0.16 miles/pixel or 820 feet/pixel). Images acquired for the surface morphology base map typically have off-vertical Sun angles (i.e., high incidence angles) and visible shadows so as to reveal clearly the topographic form of geologic features.

Date acquired: July 02, 2011
Image Mission Elapsed Time (MET): 218071882
Image ID: 452164
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: -3.15°
Center Longitude: 162.3° E
Resolution: 199 meters/pixel
Scale: This image is approximately 200 km across.
Incidence Angle: 3.2°
Emission Angle: 24.9°
Phase Angle: 28.1°

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

Tuesday, August 2, 2011

Xiao Zhao Crater


Xiao Zhao, a relatively small fresh crater, stretches its rays across this entire image, illustrating that small impacts are still quite powerful. The bright crater rays, composed of fresh material excavated by the impact, are contrasted by the older, darker surrounding surface. Another small impact crater well known for its extensive rays is Han Kan.

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 250-meter/pixel (820 feet/pixel) morphology base map or the 1-kilometer/pixel (0.6 miles/pixel) color base map. It is not possible to cover all of Mercury's surface at this high resolution during MESSENGER's one-year mission, but several areas of high scientific interest are generally imaged in this mode each week.

Date acquired: July 11, 2011
Image Mission Elapsed Time (MET): 218840609
Image ID: 489105
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 9 (996 nanometers)
Center Latitude: 14.17°
Center Longitude: 122.3° E
Resolution: 456 meters/pixel
Scale: Diameter of Xiao Zhao is 24.2 kilometers (15.0 miles)
Incidence Angle: 22.1°
Emission Angle: 34.3°
Phase Angle: 56.4°

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

Monday, August 1, 2011

Mercurian Limb and Terminator


The terminator, the division between night and day, is not as obvious in this image as in some others, but it can be seen on the bottom left portion of the planet in this image. This bottom left edge of Mercury appears to fade away, in contrast to the sunlit limb of the bottom right edge. The terrain near the terminator is heavily shadowed, and some of the neighboring surface is in the darkness of Mercury's night.

Date acquired: June 27, 2011
Image Mission Elapsed Time (MET): 217686237, 217686239, 217686245
Image ID: 433696, 433697, 433701
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 9 (996 nanometers), 7 (748 nanometers), 6 (433 nanometers) as red, green, blue
Center Latitude: -21.98°
Center Longitude: 234.5° E
Resolution: 4128 meters/pixel
Scale: The radius of Mercury is approximately 2440 km (1520 miles)

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