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Today's image is a lovely color view of the impact crater Sor Juana. The crater interior contains smooth material, probably impact melt, that embays the central peak. The rim is relatively sharp, with well developed terraces. Sor Juana does not have its own rays - the bright ray patches containing chains and clusters of secondary craters that are dotted around the scene originated at Hokusai.
Sor Juana is named for Sor Juana Inés de la Cruz (Sister Joan Agnes of the Cross), a nun and poet who lived from 1651 to 1695 in what is now Mexico. Some authorities consider her body of work to be the most important in North America until the arrival of 19th Century poets such as Dickinson and Whitman.
This image was acquired as a high-resolution targeted color observation. Targeted color observations are images of a small area on Mercury's surface at resolutions higher than the 1-kilometer/pixel 8-color base map. During MESSENGER's one-year primary mission, hundreds of targeted color observations were obtained. During MESSENGER's extended mission, high-resolution targeted color observations are more rare, as the 3-color base map covered Mercury's northern hemisphere with the highest-resolution color images that are possible.
Date acquired: April 07, 2011
Image Mission Elapsed Time (MET): 210677654, 210677650, 210677646
Image ID: 102052, 102051, 102050
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filters: 9, 7, 6 (996, 748, 433 nanometers) in red, green, and blue
Center Latitude: 50.8°
Center Longitude: 333.8° E
Resolution: 224 meters/pixel
Scale: Sor Juana crater is about 94 km (58 mi.) in diameter
Incidence Angle: 50.9°
Emission Angle: 1.4°
Phase Angle: 52.3°
North is up in this image.
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
The lower half of this image is dominated by the large, degraded crater Li Po. A Chinese poet of the Tang Dynasty who lived from 701 to 762, Li Po is also known as "Li Bai". He is famous for poems about friendship, nature, and the drinking of wine. It is said that he drowned when he reached from his boat, trying to catch the Moon's reflection in the river. Li's poem "A Quiet Night Thought" is reproduced below.
A Quiet Night Thought
In front of my bed, there is bright moonlight.
It appears to be frost on the ground.
I lift my head and gaze at the August Moon,
I lower my head and think of my hometown.
This image was acquired as part of MDIS's high-resolution stereo imaging campaign. Images from the stereo imaging campaign are used in combination with the surface morphology base map or the albedo base map to create high-resolution stereo views of Mercury's surface, with an average resolution of 200 meters/pixel. Viewing the surface under the same Sun illumination conditions but from two or more viewing angles enables information about the small-scale topography of Mercury's surface to be obtained.
Date acquired: October 29, 2011
Image Mission Elapsed Time (MET): 228371401
Image ID: 945802
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: 18.1°
Center Longitude: 324.2° E
Resolution: 153 meters/pixel
Scale: Li Po crater is about 115 km (71 mi.) in diameter
Incidence Angle: 78.6°
Emission Angle: 7.3°
Phase Angle: 78.7°
North is up in this image.
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
We've seen Thakur before - both in full color and as part of a larger view of this region of Mercury. This time, in an oblique view of its southern portion, we can see how two prominent lobate scarps deform the crater. These scarps form when one block of crust thrusts up and over another, and are thought to have formed due to a reduction in Mercury's surface area as its interior cooled and contracted. The face of a scarp indicates the direction these blocks have moved so, as we see it here, Tharkur has been squeezed from the top-right and from the bottom-left.
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 21, 2014
Image Mission Elapsed Time (MET): 48249572
Image ID: 6723137
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 3.8° S
Center Longitude: 295.8° E
Resolution: 75 meters/pixel
Scale: The left-to-right field of view in this image is approximately 80 km (50 miles) across
Incidence Angle: 65.2°
Emission Angle: 56.9°
Phase Angle: 28.2°
Orientation: North is to the lower right of the image.
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
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
Hemingway crater is seen in this color view of Mercury's surface. Hemingway is the 130-km (81-mile) diameter crater with a relatively brown floor and small patch of dark blue in its center. This impact crater has irregular depressions on its floor, which are fairly common in other impact craters and may be due to explosive volcanic events, but the low-reflectance, blue patch on the floor may point to a more complex history.
This image was acquired as a high-resolution targeted color observation. Targeted color observations are images of a small area on Mercury's surface at resolutions higher than the 1-kilometer/pixel 8-color base map. During MESSENGER's one-year primary mission, hundreds of targeted color observations were obtained. During MESSENGER's extended mission, high-resolution targeted color observations are more rare, as the 3-color base map covered Mercury's northern hemisphere with the highest-resolution color images that are possible.
Date acquired: July 15, 2014
Image Mission Elapsed Time (MET): 47756996, 47757016, 47757000
Image ID: 6688394, 6688399, 6688395
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filters: 9, 7, 6 (996, 748, 433 nanometers) in red, green, and blue
Center Latitude: 16.51°
Center Longitude: 356.9° E
Resolution: 288 meters/pixel
Scale: This scene is about 290 km (180 miles) across
Incidence Angle: 19.2°
Emission Angle: 60.3°
Phase Angle: 77.9°
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
At the left edge of this color view is a relatively fresh crater, featured previously in this oblique view. Chains of secondary craters can be seen emanating from the crater, but its bright rays have already nearly faded into the background. Bright, relatively blue rays do cross the scene from northwest to southeast, but these are the famous rays of Hokusai crater, located over 1000 km away.
This image was acquired as a high-resolution targeted color observation. Targeted color observations are images of a small area on Mercury's surface at resolutions higher than the 1-kilometer/pixel 8-color base map. During MESSENGER's one-year primary mission, hundreds of targeted color observations were obtained. During MESSENGER's extended mission, high-resolution targeted color observations are more rare, as the 3-color base map covered Mercury's northern hemisphere with the highest-resolution color images that are possible.
Date acquired: July 05, 2014
Image Mission Elapsed Time (MET): 46889179, 46889199, 46889183
Image ID: 6626955, 6626960, 6626956
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filters: 9, 7, 6 (996, 748, 433 nanometers) in red, green, and blue
Center Latitude: 34.02°
Center Longitude: 39.36° E
Resolution: 223 meters/pixel
Scale: This scene is approximately 260 km (160 miles) across
Incidence Angle: 35.5°
Emission Angle: 45.6°
Phase Angle: 78.2°
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
This small, bright crater is located in the northern plains of Mercury, southeast of the crater Stieglitz. Though it is one of many craters in the 2-5 km size range in this image, most of the others are clearly members of crater chains, created in quick succession during secondary impacts. The crater in the western portion of the image stands out from its surroundings both due to its morphology and its freshness.
This image was acquired as part of MDIS's minimum-phase-angle color campaign. Near the north polar region, the incidence angle (measured from the vertical) is always fairly high because the Sun is low on the horizon. The minimum-phase-angle color campaign acquires images under conditions that minimize the shadows in an image by viewing the surface as nearly as possible from the same direction as the Sun's illumination, which minimizes the phase angle. Images are acquired through five of the WAC's narrow-band color filters, for regions north of 60° N, at an average resolution of 500 meters/pixel. The minimum-phase-angle color campaign began in March 2013.
Date acquired: July 04, 2014
Image Mission Elapsed Time (MET): 46773193, 46773184, 46773190
Image ID: 6618773, 6618770, 6618772
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filters: 9, 7, 6 (996, 748, 433 nanometers) in red, green, and blue
Center Latitude: 68.82°
Center Longitude: 71.79° E
Resolution: 273 meters/pixel
Scale: This image is roughly 225 km (140 mi.) from corner to corner.
Incidence Angle: 73.9°
Emission Angle: 45.8°
Phase Angle: 28.0°
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
With your red-cyan glasses on, check out this stereo view inside the complex crater Catullus. Here you can see the central peaks rising above the relatively smooth floor of the crater. To the right of the peaks, a large, irregularly shaped pit sinks down below the level of the crater floor. This pit may have formed due to past volcanic activity within the impact crater.
These images were acquired as a targeted set of stereo images. Targeted stereo observations are acquired at resolutions much higher than that of the 200-meter/pixel stereo base map. These targets acquired with the NAC enable the detailed topography of Mercury's surface to be determined for a local area of interest.
Date acquired: July 25, 2014
Image Mission Elapsed Time (MET): 48654092, 48654444
Image ID: 6751776, 6751777
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 21.91°
Center Longitude: 292.8° E
Resolution: 48 meters/pixel
Scale: Pit is approximately 18 km (11 miles) across
Incidence Angle: 68.5°
Emission Angle: 11.9°
Phase Angle: 73.0°
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
In the top left part of this image is Seuss, a complex crater with hollows present on the crater's floor. In this enhanced color image, the hollows appear as bright blue-white features. Just outside of Seuss' rim, you can see some material that appears darker brown in the image. This is LRM, or Low Reflectance Material, and was probably excavated by the impactor when Seuss was formed. Extending from Seuss are bright crater rays, which are streams of ejecta that were thrown from the crater upon impact. In the bottom right of the image, you can see an irregularly shaped, orange-yellow depression that could be a volcanic vent.
This image was acquired as part of MDIS's high-resolution 3-color imaging campaign. The map produced from this campaign complements the 8-color base map (at an average resolution of 1 km/pixel) acquired during MESSENGER's primary mission by imaging Mercury's surface in a subset of the color filters at the highest resolution possible. The three narrow-band color filters are centered at wavelengths of 430 nm, 750 nm, and 1000 nm, and image resolutions generally range from 100 to 400 meters/pixel in the northern hemisphere.
Date acquired: July 08, 2014
Image Mission Elapsed Time (MET): 47121909, 47121901, 47121905
Image ID: 6643252, 6643250, 6643251
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filters: 9, 7, 6 (996, 748, 433 nanometers) in red, green, and blue
Center Latitude: 2.83º
Center Longitude: 37.11º E
Resolution: 528 meters/pixel
Scale: Seuss is 64 km (40 miles) in diameter
Incidence Angle: 15.8º
Emission Angle: 12.2º
Phase Angle: 28.0º
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
This image features a simple crater in the northern smooth plains. Superimposed on the wall of this crater is another impact crater. The smaller crater is elliptical in shape, which is most likely due to being formed on a slope on the larger crater's wall. It also appears that this impact event caused material to slide down the crater wall, which can be seen in this high-resolution image.
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: July 19, 2014
Image Mission Elapsed Time (MET): 48103544
Image ID: 6712882
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 72.72°
Center Longitude: 313.7° E
Resolution: 17 meters/pixel
Scale: This image is about 9 km (5.5 miles) across.
Incidence Angle: 78.6°
Emission Angle: 0.3°
Phase Angle: 78.9°
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Today's image shows an area in Mercury's northern latitudes crossed by a series of MASCS VIRS tracks displayed as a color composite, overlain on a MDIS base map mosaic. Craters Verdi and Janáček reside in this area, along with several unnamed craters. The VIRS footprints are smaller, each covering less area, in the northern hemisphere due to MESSENGER's elliptical orbit.
The VIRS composite shows hundreds of individual footprints tracks (minimum 100-200 m across and 3-4 km long) taken from different directions and altitudes. In locations where multiple footprints cover the same area, the footprint with the best illumination for mineralogical interpretation (usually the lowest incidence angle where shadows are minimized) is used for making the map. In the MDIS mosaic, some brightness variations are due to tiling of images taken at different illuminations.
Date Created: July 27, 2014
Instruments: Visible and Infrared Spectrograph (VIRS) of the Mercury Atmosphere and Surface Composition Spectrometer (MASCS) and Mercury Dual Imaging System (MDIS)
VIRS Color Composite Wavelengths: 575 nm as red, 415 nm/750 nm as green, 310 nm/390 nm as blue
Center Latitude: 57.7°
Center Longitude: 197.5° E
Resolution: 1 km/pixel
Scale: Verdi (top left) crater is 145 km (90 miles) in diameter
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
This high-resolution image features hollows within an unnamed crater. Hollows often have bright halos and usually form in or around craters. Here, the hollows are forming on the crater floor, along the base of the crater wall, and on the top of the central peak.
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: October 13, 2012
Image Mission Elapsed Time (MET): 258630853
Image ID: 2758246
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 50.63°
Center Longitude: 320.6° E
Resolution: 15 meters/pixel
Scale: This image is about 16 km (10 miles) across.
Incidence Angle: 76.8°
Emission Angle: 15.0°
Phase Angle: 91.9°
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Today's image shows three oblique mosaics of Hokusai, a complex crater in Mercury's northern hemisphere. The top mosaic features a view of Hokusai where north is to the left. The bottom left is a color mosaic that also has north to the left. In the bottom right is mosaic with a high incidence angle where north is now to the right. The high incidence angle emphasizes topography differences because the sun's low angle creates long shadows. Evident in all of these mosaics are Hokusai's smooth impact melt covered floor, central peak, ejecta blanket, and terraced walls.
The top mosaic 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.
The bottom left color image was acquired as a targeted high-resolution 11-color image set. Acquiring 11-color targets is a new campaign that began in March 2013 and that utilizes all of the WAC's 11 narrow-band color filters. Because of the large data volume involved, only features of special scientific interest are targeted for imaging in all 11 colors.
The bottom right mosaic was acquired as part of MDIS's high-incidence-angle base map. The high-incidence-angle base map complements the surface morphology base map of MESSENGER's primary mission that was acquired under generally more moderate incidence angles. High incidence angles, achieved when the Sun is near the horizon, result in long shadows that accentuate the small-scale topography of geologic features. The high-incidence-angle base map was acquired with an average resolution of 200 meters/pixel.
Instruments: Wide Angle Camera (WAC) and Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
WAC filters: 9, 7, 6 (996, 748, 433 nanometers) in red, green, and blue for color mosaic
Center Latitude: 57.66°
Center Longitude: 16.58° E
Scale: Hokusai is about 85 km (53 miles) in diameter.
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
This image, located north of Rachmaninoff, features a possible volcanic vent to the east and an expanse of terrain that appears blue in this color view to the west. The depression's orange-yellow color and irregular shape are similar to other possible volcanic vents on Mercury. To the west of the large vent is a crater with an orange, irregularly shaped depression on its floor that may also be a vent. Vents on Mercury are indicative of explosive volcanism that was prevalent in Mercury's past.
This image was acquired as a high-resolution targeted color observation. Targeted color observations are images of a small area on Mercury's surface at resolutions higher than the 1-kilometer/pixel 8-color base map. During MESSENGER's one-year primary mission, hundreds of targeted color observations were obtained. During MESSENGER's extended mission, high-resolution targeted color observations are more rare, as the 3-color base map covered Mercury's northern hemisphere with the highest-resolution color images that are possible.
Date acquired: July 03, 2014
Image Mission Elapsed Time (MET): 46686728, 46686748, 46686732
Image ID: 6612580, 6612585, 6612581
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filters: 9, 7, 6 (996, 748, 433 nanometers) in red, green, and blue
Center Latitude: 36.10°
Center Longitude: 54.93° E
Resolution: 215 meters/pixel
Scale: The crater with a possible vent on its floor is about 20 km (12.4 miles) in diameter.
Incidence Angle: 40.6°
Emission Angle: 39.4°
Phase Angle: 78.0°
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Today's image features a small, simple impact crater on Mercury's northern plains. The superimposed track is a set of altimetry measurements by the Mercury Laser Altimeter (MLA) that resolves the bowl-shaped morphology characteristic of simple craters. This morphology is evident in the topographic profile on the right of this image that displays how the crater's depth changes from point A to point B.
Instrument: Mercury Laser Altimeter (MLA)
MLA Track: MLASCIRDRAPLFN1112211457
Crater's Center Latitude: 78.1°
Crater's Center Longitude: 327.5° E
Scale: The crater has a diameter of 4.53 km (2.81 miles)
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Rikyü is an impact crater named for Sen no Rikyü, the master who was central in the development of the Japanese tea ceremony. Rikyü sits in Mercury's northern plains and is expected to host water ice because of its persistently shadowed interior and radar-bright signature. Today's image features a northwestern segment of the crater wall, where a 4.1 km-wide simple crater has resulted from an impact on Rikyü's rim. This high-resolution image also provides a fantastic view of the tiny craters that mark the crater's 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: August 04, 2012
Image Mission Elapsed Time (MET): 252610116
Image ID: 2330144
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 80.17°
Center Longitude: 335.4° E
Resolution: 13 meters/pixel
Scale: The simple crater in the lower left corner is approximately 4.1 km wide (2.5 miles)
Incidence Angle: 82.8°
Emission Angle: 44.8°
Phase Angle: 127.6°
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Today's color image features a small crater in Mercury's northern hemisphere. This relatively young crater is highlighted by its striking white rays, which contrast the darker, surrounding terrain of low reflectance material. The bright rays result from fine-grained and relatively unweathered material that was ejected and deposited by the impact.
This image was acquired as a targeted high-resolution 11-color image set. Acquiring 11-color targets is a new campaign that began in March 2013 and that utilizes all of the WAC's 11 narrow-band color filters. Because of the large data volume involved, only features of special scientific interest are targeted for imaging in all 11 colors.
Date acquired: July 08, 2014
Image Mission Elapsed Time (MET): 47178430, 47178426, 47178424
Image ID: 6647334, 6647332, 6647331
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filters: 9, 7, 6 (996, 748, 433 nanometers) in red, green, and blue
Center Latitude: 43.97°
Center Longitude: 34.76° E
Resolution: 348 meters/pixel
Scale: The crater on the right of this image is approximately 16 km (10 miles) across
Incidence Angle: 45.9°
Emission Angle: 1.6°
Phase Angle: 44.9°
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Today's video is a MASCS VIRS raster scan of Lermontov in Mercury's mid latitudes. Raster scans return a large number of spectra for targeted areas of interest. This movie was created from 258 VIRS spectra, taken 1 to 5 seconds apart. The VIRS color composite has been overlain on an MDIS image of Lermontov, showing that the crater center is red and thus brighter at longer wavelengths compared to the average Mercury terrain.
The VIRS composite shows hundreds of individual footprints tracks (minimum 100-200 m across and 3-4 km long) taken from different directions and altitudes. In locations where multiple footprints cover the same area, the footprint with the best illumination for mineralogical interpretation (usually the lowest incidence angle where shadows are minimized) is used for making the map.
Date Observed: August 8, 2013
Date Created: July 29, 2014
Instruments: Visible and Infrared Spectrograph (VIRS) of the Mercury Atmosphere and Surface Composition Spectrometer (MASCS) and Mercury Dual Imaging System (MDIS)
VIRS Color Composite Wavelengths: 575 nm as red, 415 nm/750 nm as green, 310 nm/390 nm as blue
Initial Latitude of Scan: 14.0°
Initial Longitude of Scan: 310.8° E
Final Latitude of Scan: 17.8°
Final Longitude of Scan: 310.0° E
Resolution: 0.25 km/pixel
Scale: Lermontov is 166 km (103 mi.) in diameter
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
The left column of images shows MASCS VIRS interpolated color composites of Kertesz (top), Dominici (middle), and an unnamed crater (bottom). The middle column shows the VIRS color composite of spectral footprints, and the left column shows monochrome MDIS images for the same areas. Yellow areas are highly reflective and thought to be relatively young, exhibiting fewer effects of space weathering. Kertesz and Dominici are also known to contain hollows, which are shallow depressions with younger surfaces likely caused by the loss of volatiles.
The VIRS composite shows hundreds of individual footprints tracks (minimum 100-200 m across and 3-4 km long) taken from different directions and altitudes. In locations where multiple footprints cover the same area, the footprint with the best illumination for mineralogical interpretation (usually the lowest incidence angle where shadows are minimized) is used for making the map. Where footprints are sparse, interpolation is required for full spatial coverage.
Date Created: July 28, 2014
Instruments: Visible and Infrared Spectrograph (VIRS) of the Mercury Atmosphere and Surface Composition Spectrometer (MASCS) and Mercury Dual Imaging System (MDIS)
VIRS Color Composite Wavelengths: 575 nm as red, 415 nm/750 nm as green, 310 nm/390 nm as blue
Center Latitudes: 27.3° (top); 1.18° (middle); -3.6° (bottom)
Center Longitudes: 146.1° E (top); 323.5° E (middle); 60.9° E (bottom)
Resolution: 0.5 km/pixel
Scale: Kertesz crater (top) has a diameter of 32 km (20 mi.); Dominici crater (middle) has a diameter of 20 km (12 mi.)
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
The top image is a MASCS VIRS color composite of Rembrandt, Mercury's second largest impact basin. The bottom image is a MDIS color mosaic of the same area. Rembrandt's rim appears blue in both images, indicating low reflectance relative to its center in the VIRS image. Some small, fresh craters appear in yellow and are highly reflective in VIRS.
The VIRS composite shows hundreds of individual footprints tracks (minimum 100-200 m across and 3-4 km long) taken from different directions and altitudes. In locations where multiple footprints cover the same area, the footprint with the best illumination for mineralogical interpretation (usually the lowest incidence angle where shadows are minimized) is used for making the map.
Date Created: July 27, 2014
Instruments: Visible and Infrared Spectrograph (VIRS) of the Mercury Atmosphere and Surface Composition Spectrometer (MASCS) and Mercury Dual Imaging System (MDIS)
VIRS Color Composite Wavelengths: 575 nm as red, 415 nm/750 nm as green, 310 nm/390 nm as blue
MDIS Color Wavelengths: 1000nm as red, 750nm as green, 430 as blue
Center Latitude: -34.3°
Center Longitude: 87.2° E
Resolution: 1 km/pixel
Scale: Rembrandt is 715 km (444 mi.) in diameter
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
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