Tuesday, February 21, 2012

The Scarp in Rembrandt


The long scarp trending vertically on the left-side of this image is located in the interior of the large 715-kilometer diameter Rembrandt impact basin. The interior of Rembrandt hosts not only this compressional scarp but also a set of radial extensional troughs. View these links to see Rembrandt in color or in 3D.

Date acquired: February 07, 2012
Image Mission Elapsed Time (MET): 237089673
Image ID: 1363507
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: -35.48°
Center Longitude: 82.5° E
Resolution: 210 meters/pixel
Scale: This image is approximately 210 kilometers (130 miles) across
Orientation: North is toward the upper left corner
Incidence Angle: 62.5°
Emission Angle: 36.9°
Phase Angle: 78.1° [or 67.4°; two phase angles were listed for this photo]

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

Monday, February 20, 2012

Impact Crater with Impact Melt


This high-resolution color image shows a 14-kilometer diameter crater that is relatively young, as indicated by the bright rays that cross the neighboring features. A dark "tongue" of impact melt, which has a bluer color than the nearby surface, appears to have flowed out of the crater.

Date acquired: May 16, 2011
Image Mission Elapsed Time (MET): 214069807, 214069811, 214069815
Image ID: 261719, 261720, 261721
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: -8.82°
Center Longitude: 254.9° E
Resolution: 294 meters/pixel
Scale: The center crater has a diameter of approximately 14 kilometers (9 miles)
Incidence Angle: 41.8°
Emission Angle: 25.6°
Phase Angle: 67.4°

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

Sunday, February 19, 2012

Amaral Crater


Named in 2008 for the Brazilian painter Tarsila do Amaral, Amaral crater was imaged during MESSENGER's first Mercury flyby and discovered to contain bright central peaks that were relatively blue in color compared to the surrounding terrain. The peaks resembled those of Eminescu in color, now known to be the location of an impressive collection of hollows. This spectacular image of Amaral highlights the topography of the peaks inside the crater but doesn't show wide-spread hollows as seen within Eminescu, though there may be a hint that perhaps the bright tips of Amaral's peaks do host hollows.

Date acquired: February 04, 2012
Image Mission Elapsed Time (MET): 236873588
Image ID: 1353328
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: -26.44.°
Center Longitude: 118.2.° E
Resolution: 80 meters/pixel
Scale: Amaral has a diameter of 109 kilometers (68 miles)
Orientation: North is to the left
Incidence Angle: 85°
Emission Angle: 56°
Phase Angle: 29°

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

Thursday, February 16, 2012

Kuiper Crater


This high-resolution enhanced color view of Kuiper crater shows not just the bright rays that extend out from this relatively young crater but also the redder color of Kuiper's ejecta blanket. The redder color may be due to a compositionally distinct material excavated from depth by the impact that formed Kuiper.

Date acquired: September 02, 2011
Image Mission Elapsed Time (MET): 223443634, 223443638, 223443654
Image ID: 708128, 708129, 708133
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: -11.97°
Center Longitude: 328.4° E
Resolution: 380 meters/pixel
Scale: Kuiper has a diameter of 62 kilometers (39 miles)
Incidence Angle: 33.4°
Emission Angle: 21.4°
Phase Angle: 54.8°

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

Wednesday, February 15, 2012

Xiao Zhao and Eastman Craters


The bright rays of Xiao Zhao dominate this scene. These rays indicate that Xiao Zhao is a relatively young crater. Eastman crater can be seen to the southwest of Xiao Zhao. The eight different color filters of the WAC that are used to create the color base map have central wavelengths of 430, 480, 560, 630, 750, 830, 900, and 1000 nm. The images acquired through these narrow-band filters are combined to create color images that accentuate color differences on Mercury's surface. As an example, this image was created by using three images acquired as part of the color base map with the central wavelengths of 1000, 750, and 430 nm displayed in red, green, and blue, respectively. This particular combination allows the visualization of details, some of which would be invisible to the human eye.

Date acquired: December 29, 2011
Image Mission Elapsed Time (MET): 233687507, 233687511, 233687527
Image ID: 1199649, 1199650, 1199654
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: 9.6°
Center Longitude: 125.8° E
Resolution: 443 meters/pixel
Scale: The rayed crater Xiao Zhao is 24 km (15 mi.) in diameter.
Incidence Angle: 26.9°
Emission Angle: 14.1°
Phase Angle: 28.0°

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

Tuesday, February 14, 2012

Hovnatanian Crater


Hovnatanian crater was formed by an object that impacted at a very oblique angle, causing the crater to appear elliptical. Although impacts at most angles produce circular craters, impacts with incidence angles less than 15º (from the horizontal) will create elliptical craters. The rays of Hovnatanian form a "butterfly" pattern, which also indicates an oblique impact.

Date acquired: January 16, 2012
Image Mission Elapsed Time (MET): 235218286
Image ID: 1273501
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: -7.7°
Center Longitude: 172.6° E
Resolution: 58 meters/pixel
Scale: Hovnatanian crater is approximately 33 km (21 mi.) long.
Incidence Angle: 77.3°
Emission Angle: 55.6°
Phase Angle: 132.9°

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

Monday, February 13, 2012

Complex Crater with Hollows


This interesting complex crater exhibits many hollows along its floor and central peak complex. The hollows have a very high albedo, which makes this crater stand out prominently (for example, the crater can be seen clearly near the right hand side of this image).

Date acquired: January 26, 2012
Image Mission Elapsed Time (MET): 236105127
Image ID: 1316385
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: -2.8°
Center Longitude: 353.6° E
Resolution: 119 meters/pixel
Scale: The large crater is approximately 90 km (56 mi.) across.
Incidence Angle: 67.4°
Emission Angle: 56.9°
Phase Angle: 124.4°

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

Sunday, February 12, 2012

De Graft Crater


De Graft crater was named for 20th century Ghanaian playwright, poet, and novelist Joe de Graft following MESSENGER's second flyby of the innermost planet. De Graft is a complex crater that hosts numerous bright hollows on its floor. This image is a mosaic of three NAC images taken as a sequence designed to target the crater.

Date acquired: January 23, 2012
Image Mission Elapsed Time (MET): 235766888, 235766929, 235766969
Image ID: 1300010, 1300011, 1300012
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 21.90°
Center Longitude: 1.78° E
Resolution: 57 meters/pixel
Scale: De Graft crater is approximately 68 km (42 mi.) in diameter.
Incidence Angle: 73.5°
Emission Angle: 37.1°
Phase Angle: 110.7°

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

Saturday, February 11, 2012

From Terminator to Limb


This stunning view includes both the terminator and the limb. Basho crater, an 80-km-diameter, complex crater with a prominent central peak, can be seen near the center of the scene.

Date acquired: January 11, 2012
Image Mission Elapsed Time (MET): 234794915
Image ID: 1253094
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: -33.9°
Center Longitude: 188.4° E
Resolution: 713 meters/pixel
Scale: Mercury is 2440 km (1516 mi.) in diameter

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

Monday, February 6, 2012

Living in Anonymity


This image, taken with the Wide Angle Camera (WAC), shows an unnamed crater in Mercury's northern hemisphere. This complex crater displays bright central peaks and terraced walls. It may also contain hollows at its center--shallow, bright impressions which were a surprising find in some of MESSENGER's high-resolution images.

Date acquired: December 02, 2011
Image Mission Elapsed Time (MET): 231308591
Image ID: 1084977
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: 39.68°
Center Longitude: 111.0° E
Resolution: 107 meters/pixel
Scale: The large crater is about 75 km (47 miles) in diameter
Incidence Angle: 73.7°
Emission Angle: 6.4°
Phase Angle: 73.5°

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

Sunday, February 5, 2012

Hollows or Horcruxes


This image, taken with the Narrow Angle Camera (NAC), shows an area of hollows on the floor of Raditladi basin. Hollows were first discovered on the surface of Mercury during MESSENGER's orbital mission and have not been seen on the Moon or on any other rocky planetary bodies. These bright, shallow depressions may have been formed by the loss of volatile materials. This same region has also been imaged in color.

Date acquired: January 02, 2012
Image Mission Elapsed Time (MET): 233984961
Image ID: 1213990
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 26.60°
Center Longitude: 120.5° E
Resolution: 47 meters/pixel
Scale: This image is 73 km across (45 miles) from the left point to the right point.
Incidence Angle: 33.3°
Emission Angle: 22.0°
Phase Angle: 51.5°

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

Saturday, February 4, 2012

Northern Lights


This image, taken with the Wide Angle Camera (WAC), shows an unnamed complex crater in Mercury's northern hemisphere. The crisp morphology of the terraced walls and central peak, and the high-reflectance ejecta blanket and rays surrounding the crater, indicate that the crater is relatively young. Also visible are many secondary craters, possibly resulting from the impact that formed this crater to the west.

Date acquired: January 04, 2012
Image Mission Elapsed Time (MET): 234155258
Image ID: 1222319
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: 51.54°
Center Longitude: 95.26° E
Resolution: 176 meters/pixel
Scale: The complex crater is 33 km (20 miles) in diameter
Incidence Angle: 61.6°
Emission Angle: 15.6°
Phase Angle: 48.5°

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

Wednesday, February 1, 2012

Eminescu Crater


This image, taken with the Narrow Angle Camera (NAC), shows the crater Eminescu. Named for the nineteenth century Romanian poet Mihai Eminescu, Eminescu displays bright hollows at its center. These shallow, irregular depressions were a surprising find in MESSENGER high-resolution images, and the possible causes of their formation are still being studied.

Date acquired: January 03, 2012
Image Mission Elapsed Time (MET): 234069368
Image ID: 1218106
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 4 (558 nanometers)
Center Latitude: 10.29°
Center Longitude: 113.9° E
Resolution: 469 meters/pixel
Scale: Eminescu crater is about 130 km (80 miles) in diameter.
Incidence Angle: 26.5°
Emission Angle: 23.6°
Phase Angle: 50.2°

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

Monday, January 30, 2012

Ray Systems for Kuiper, Debussy and Hokusai Craters


This image shows two of the most prominent rayed craters on the surface of Mercury. In the top center is Kuiper, named for Dutch-American planetary astronomer and Mariner 10 team member Gerard Kuiper (1905-1973). At the right edge is the 80-km diameter crater named for French composer Claude Debussy (1862-1918). The impacts that formed these craters ejected target materials for great distances across the planet's surface, and the image shows areas where the two sets of rays intersect. Another group of rays, entering the image from the top right, were deposited by the impact that formed Hokusai crater, far to the north. Hokusai was a Japanese artist who lived from 1760-1849.

Date acquired: October 06, 2008
Image Mission Elapsed Time (MET): 131772995
Image ID: 6793
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: -31.41°
Center Longitude: 326.4° E
Resolution: 2800 meters/pixel
Scale: The distance between Kuiper and Debussy is about 1940 km (1200 miles)

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

Sunday, January 29, 2012

Ribbons and Chains


This view shows several groups of similar-sized craters arranged roughly in lines. Crater chains are sometimes formed by volcanic eruptions, but the craters here were made by secondary impacts. The excavation of a large crater or basin can throw out blocks of material along radial trajectories. The blocks then sometimes strike the surface nearly in the same location, producing secondary crater chains. Finer ejecta may form the bright ribbons known as crater rays.

Date acquired: June 07, 2011
Image Mission Elapsed Time (MET): 215937760
Image ID: 349758
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: 35.48°
Center Longitude: 123.4° E
Resolution: 236 meters/pixel
Scale: The edges of the image are about 120 km (75 mi.) long.
Incidence Angle: 63.0°
Emission Angle: 11.7°
Phase Angle: 51.3°

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

Saturday, January 28, 2012

Two Views of Berkel Crater


Today's offering shows two views of the crater Berkel. The image on the left is a monochrome image obtained when the Sun was lower on the horizon than when the color image on the right was collected. As a result, the left image emphasizes the topography of the surface (due to the presence of shadowing), whereas the image on the right is dominated by inherent differences in reflectance and color. The impact that formed Berkel excavated dark subsurface material and deposited it around the crater's rim. The presence of this low reflectance material causes the floor of the crater to appear black in the color image.

The image on the left is part of MDIS's high-resolution surface morphology base map. The surface morphology base map covers 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.

The image on the right image is part of MDIS's color base map. The color base map is composed of WAC images taken through eight different narrow-band color filters and covers more than 90% of Mercury's surface with an average resolution of 1 kilometer/pixel (0.6 miles/pixel). The highest-quality color images are obtained for Mercury's surface when both the spacecraft and the Sun are overhead, so these images typically are taken with viewing conditions of low incidence and emission angles. The false-color presentation here has images taken through the 750-nm, 560-nm and 480-nm filters as red-green-blue.

Scale: Berkel crater is about 22 km (14 mi.) in diameter
Location: Berkel is located at -13.75° latitude, 26.9° E longitude
Instrument: Mercury Dual Imaging System (MDIS)

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

Friday, January 27, 2012

Messenger's First Image of 2012


Shown here is the first MESSENGER image from 2012! Though this image was acquired on January 1, it wasn't downlinked from the spacecraft until this week. The spacecraft has two solid-state recorders, which enable data to be stored on the spacecraft, and the mission uses a system of priorities to determine which data are downlinked. Often images are sent back to Earth within a few days of being acquired but occasionally longer times between image acquisition and downlink occur.

The year 2011 was an historic one for the MESSENGER mission, and there is much to look forward to in 2012. In 2012, the mission will continue to return new data from the Solar System's innermost planet nearly every day, completing its one-year primary mission in March and beginning new scientific observation campaigns in a one-year extended mission.

This image was acquired as part of MDIS's campaign to monitor the south polar region of Mercury. By imaging the polar region every four MESSENGER orbits as illumination conditions change, features that were in shadow on earlier orbits can be discerned and any permanently shadowed areas can be identified after repeated imaging over one solar day. During MESSENGER's one-year mission, MDIS's WAC is used to monitor the south polar region for the first Mercury solar day (176 Earth days), and MDIS's NAC is used for imaging the south polar region during the second Mercury solar day.

Date acquired: January 1, 2012
Image Mission Elapsed Time (MET): 0233869628
Image ID: 1207852
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: -83.30°
Center Longitude: 41.44° E
Resolution: 298 meters/pixel
Scale: This image is approximately 300 kilometers (190 miles) across
Incidence Angle: 91.6°
Emission Angle: 8.7°
Phase Angle: 99.0°

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

Thursday, January 26, 2012

Two Impact Crater Peaks


This beautiful, unnamed crater is found within the Caloris impact basin, and formed partially atop another crater of similar size to its northwest. On the right-hand side of the image you can see the crater's central peak; at the upper left, you can see where the crater wall intersects what is left of the older crater's central peak.

Date acquired: December 24, 2011
Image Mission Elapsed Time (MET): 233221689
Image ID: 1177142
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 36.6°
Center Longitude: 166.4° E
Resolution: 29 meters/pixel
Scale: Scene is approximately 30 km (19 miles) across
Incidence Angle: 36.6°
Emission Angle: 33.1°
Phase Angle: 69.7°

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

Wednesday, January 25, 2012

Impact Crater on Pantheon Fossae


The troughs of Pantheon Fossae extend across this scene, located between Cunningham and Apollodorus craters. This 14-km crater appears to have formed after Pantheon Fossae, with its ejecta covering the troughs.

Date acquired: December 25, 2011
Image Mission Elapsed Time (MET): 233263747
Image ID: 1179175
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 31.1°
Center Longitude: 159.8° E
Resolution: 40 meters/pixel
Scale: The large impact crater is approximately 14 km (8 miles) in diameter
Incidence Angle: 31.2°
Emission Angle: 4.1°
Phase Angle: 32.5°

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

Sunday, January 15, 2012

Apollodorus Crater and the Pantheon Fossae


This spectacular image contains the crater Apollodorus and some of the Pantheon Fossae structure, a complex system of extensional troughs located near the center of the Caloris basin. Although Apollodorus is located close to the center of Pantheon Fossae, the crater and trough system appear to be unrelated. North is down in this image.

Date acquired: July 28, 2011
Image Mission Elapsed Time (MET): 220331898
Image ID: 560776
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: 31.5°
Center Longitude: 165.0° E
Resolution: 115 meters/pixel
Scale: Apollodorus crater is approximately 42 km (26 mi.) in diameter.
Incidence Angle: 83.1°
Emission Angle: 38.3°
Phase Angle: 121.4°

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