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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
These images highlight the spectacular Vivaldi peak-ring basin and its ejecta blanket. The top image was acquired with MESSENGER's Wide Angle Camera, and the white box shows the location of the bottom image, acquired about a minute later with the Narrow Angle Camera. While Vivaldi is stunning, the real purpose of these images was to check and improve the geometric calibration of the cameras. As light passes through the lenses of a camera, it bends such that subtle geometric distortions of the scene occur, and for the Wide Angle Camera things like the focal length can shift by small amounts depending on which filter is being used. These images were part of a series that is designed to make sure we can map each pixel of the NAC and WAC to a geographic latitude and longitude as accurately as possible, and that the coordinates from the two cameras match perfectly. The two images shown here are also a good reminder of just how much higher resolution the NAC provides compared to the WAC.
Date acquired: July 29, 2014
Image Mission Elapsed Time (MET): 48972719, 48972797
Image ID: 6774306, 6774309
Instrument: Wide Angle Camera (WAC) and Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 12.08°
Center Longitude: 278.1° E
Resolution: 57 and 426 meters/pixel
Scale: Vivaldi is approximately 213 km (132 miles) in diameter
Incidence Angle: 82.2°
Emission Angle: 14.3°
Phase Angle: 96.5°
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
This color view of Mercury's surface highlights what may be an old volcanic vent. Just to the right of center, within a brown-red patch, is an irregularly shaped 30-km depression, in this case the irregular shape is a bit like a butterfly. While most of these suspected volcanic vents are located within impact craters (like this one), the butterfly-shaped vent is not clearly associated with any crater. It also appears that it may be older than other vents, resulting in more subdued details and colors.
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 11, 2014
Image Mission Elapsed Time (MET): 47381178, 47381170, 47381174
Image ID: 6661702, 6661700, 6661701
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: 32.08°
Center Longitude: 21.71° E
Resolution: 243 meters/pixel
Scale: This scene is approximately 250 km (155 miles) across
Incidence Angle: 32.7°
Emission Angle: 0.5°
Phase Angle: 33.2°
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
Red-cyan glasses will help you see the impressive heights of Paramour Rupes in this 3D view. Paramour is a large cliff (well over 600 meters high at places!) that formed when one block of crust was thrust forward over another, resulting in a feature known as a lobate scarp. Paramour Rupes is located to the southwest of the Caloris basin, and the small knobs that litter the scene are thought to be blocks of ejecta from the Caloris impact event. For ease of stereo viewing, this anaglyph has been rotated so that north is toward the left.
This image pair was 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: June 18, 2014
Image Mission Elapsed Time (MET): 45386688, 45387906
Image ID: 6520353, 6520362
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: -4.99°
Center Longitude: 146.3°E
Resolution: 110 meters/pixel
Scale: This scene is approximately 110 km (68 miles) across
Incidence Angle: 63.8°
Emission Angle: 37.2°
Phase Angle: 97.7°
Image credit: NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington
In and of itself, this image of a portion of a north-south-trending lobate scarp, situated midway between Firdousi crater and Caravaggio basin, is not particularly noteworthy. Look a little closer, however, and this little part of Mercury's surface takes on a strange, pitted appearance. A number of shallow, teardrop-shaped depressions occur throughout the image, aligned from the top-left to the bottom-right. This distinctive surface texture is likely caused by debris thrown out by nearby impacts (there is a crater 11 km, or 7 miles, in diameter to the southeast that might be responsible, for example). If so, then these small depressions are effectively secondary impact craters-but not quite like those we're used to seeing. The difference between these depressions and what we normally think of as secondary craters is likely due to size: as MESSENGER gets closer to the surface of Mercury, we are seeing more and more fascinating features at ever greater resolutions. What else will we see before MESSENGER's adventure ends?
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 31, 2014
Image Mission Elapsed Time (MET): 49172453
Image ID: 6788651
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 1.2°
Center Longitude: 77.7° E
Resolution: 23 meters/pixel
Scale: The left-to-right field of view in this image is 21 km (13 miles) across
Incidence Angle: 77.1°
Emission Angle: 1.9°
Phase Angle: 78.9°
Orientation: 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
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