Wednesday, March 14, 2012

Rachmaninoff Impact Basin


This image, taken with the Wide Angle Camera (WAC), provides a master class in Mercury surface features and the geologic processes that formed them. The image shows a portion of Rachmaninoff, a double-ring basin named for the early twentieth century Russian composer, pianist and conductor Sergei Rachmaninoff. In this region, we see the remnants of an inner peak ring, with hollows dusting the tops of the peaks in both the inner and outer rings. Also visible is the basin's main rim scarp beginning in the left corner of the image and extending to the southeast. The crater floor contains a number of regions of high-reflectance material, as well as polygonal valleys called graben (located near the top of the image, at the basin's center). Graben are formed by forces pulling apart the surface; these extensional forces are in contrast to the tectonic contraction we typically see all over Mercury and may be related to cooling of the smooth volcanic plains that cover the floor.

Date acquired: February 06, 2012
Image Mission Elapsed Time (MET): 237042001
Image ID: 1361459
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: 25.53°
Center Longitude: 57.51° E
Resolution: 136 meters/pixel
Scale: This image is 238 km (148 miles) wide from left corner to right corner.
Incidence Angle: 37.9°
Emission Angle: 36.3°
Phase Angle: 74.2°

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

Tuesday, March 13, 2012

Lobate Scarp Within Rembrandt Basin


This image, taken with the Narrow Angle Camera (NAC), shows a simple crater within Rembrandt Basin. Running through the crater is a lobate scarp, formed as Mercury's large iron core cooled and contracted, generating compressive forces that pushed one section of the planet's crust over the top of another section. Determining the geometry of such scarps and the time periods when deformation occurred can help scientists to understand the thermal history of the planet.

Date acquired: February 05, 2012
Image Mission Elapsed Time (MET): 236961590
Image ID: 1357377
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: -29.79°
Center Longitude: 83.26° E
Resolution: 184 meters/pixel
Scale: The large crater at the bottom of the image is about 59 km (37 miles) in diameter.
Incidence Angle: 57.8°
Emission Angle: 39.0°
Phase Angle: 78.2°

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

Monday, March 12, 2012

Sher-Gil Crater


Impact craters serve as probes into a planet's subsurface, excavating and exposing material from depth that would be otherwise unobservable. Thus the study of impact crater deposits can help to elucidate the geological history of the target region. In this image, the crater Sher-Gil has exposed low-reflectance material, particularly in its eastern wall and at two concentrated points on the north and south rim. Younger, bright features called hollows dot the dark parts of the crater.

Date acquired: December 01, 2011
Image Mission Elapsed Time (MET): 231267850
Image ID: 1082997
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: -45.06°
Center Longitude: 135.3° E
Resolution: 102 meters/pixel
Scale: Sher-Gil crater is about 76 km (47 mi.) in diameter
Incidence Angle: 59.6°
Emission Angle: 15.9°
Phase Angle: 65.0°

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

Sunday, March 11, 2012

Unnamed Complex Crater with Impact Melt


This image, taken with the Narrow Angle Camera (NAC), gives us a spectacular close-up look at an unnamed complex crater in Mercury's northern hemisphere. At the top we see wall terraces containing ponds of impact melt. At the bottom is the crater's central peak, which displays bright material and possibly hollows near its summit.

Date acquired: February 01, 2012
Image Mission Elapsed Time (MET): 236617390
Image ID: 1340969
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 50.84°
Center Longitude: 93.60° E
Resolution: 20 meters/pixel
Scale: The edges of the image are about 10 km (6 mi.) long.
Incidence Angle: 66.6°
Emission Angle: 10.8°
Phase Angle: 55.7°

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

Saturday, March 10, 2012

Bright Rayed Crater


This image, taken with the Wide Angle Camera (WAC), shows a bright rayed crater in Mercury's southern hemisphere. The rays, created when target material was ejected out onto the surface during the impact that formed the crater, will gradually fade over time due to the effects of Mercury's harsh space environment. The crater is deep enough that the local surface layers were penetrated, exposing low reflectance material (LRM) beneath.

Date acquired: February 06, 2012
Image Mission Elapsed Time (MET): 237000734
Image ID: 1359421
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 9 (996 nanometers)
Center Latitude: -17.70°
Center Longitude: 67.69° E
Resolution: 414 meters/pixel
Scale: The central rayed crater is 24 km (15 miles) in diameter.
Incidence Angle: 41.2°
Emission Angle: 12.0°
Phase Angle: 52.3°

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

Friday, March 9, 2012

Southern Anonymity


This scene captures an area of Mercury's southern hemisphere where none of the craters have yet had names approved by the International Astronomical Union. A variety of terrain types are found in this region: rugged heavily cratered older surfaces, smooth plains on crater floors, and younger bright-rayed craters.

Date acquired: September 20, 2011
Image Mission Elapsed Time (MET): 225001789
Image ID: 783910
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: -55.50°
Center Longitude: 16.58° E
Resolution: 361 meters/pixel
Scale: The edges of this image are about 360 km (220 mi.) long
Incidence Angle: 57.9°
Emission Angle: 1.3°
Phase Angle: 58.9°

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

Thursday, March 8, 2012

Beethoven Basin Elevation Map


This elevation map of the Beethoven basin is color-coded to show the height of features on Mercury's surface. Mercury lacks a "sea level," so the zero-point reference elevation is defined to be the mean planetary radius of 2440 km. Blue areas, such as within Bello crater on the floor of Beethoven, have negative elevations. The red and white areas to the southwest are more than 8 km higher than the lowest points in this area.

Center Latitude: -20°
Center Longitude: 236° E
Scale: Beethoven basin is ~650 km (404 miles) in diameter
Image information: A digital terrain model (DTM) derived from Mercury Dual Imaging System (MDIS) stereo images. The lateral spacing is 330 meters and the map is in stereographic (conformal) projection. The image is taken from abstract number 1913 submitted to the 2012 Lunar and Planetary Science Conference, by Frank Preusker and colleagues.

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

Wednesday, March 7, 2012

Hesiod Crater


The crater at the western corner of this image is Hesiod. The northern and eastern parts of Hesiod's rim are marked by irregular depressions. These depressions are thought to be vents from which explosive (pyroclastic) volcanic eruptions originated. The high-reflectance areas on the wall of the crater just to the northeast of Hesiod and at the top of the image share color characteristics with other pyroclastic deposits known on Mercury. Pyroclastic eruptions are driven by volatile compounds, and MESSENGER has revealed that Mercury has a higher abundance of volatile elements than was previously expected.

Date acquired: September 07, 2011
Image Mission Elapsed Time (MET): 223922395
Image ID: 730933
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: -57.84°
Center Longitude: 329.6° E
Resolution: 193 meters/pixel
Scale: Hesiod crater is about 100 km (62 miles) in diameter
Incidence Angle: 62.7°
Emission Angle: 21.7°
Phase Angle: 84.5°

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

Sunday, February 26, 2012

Firdousi Crater


Firdousi is a relatively fresh impact crater approximately 96 kilometers (60 miles) in diameter. Its abundant secondary craters dominate the surroundings, and many have haloes of high-reflectance, relatively blue ejecta.

Date acquired: August 14, 2011
Image Mission Elapsed Time (MET): 221844487, 221844483, 221844479
Image ID: 632390, 632389, 632388
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: 4.19°
Center Longitude: 65.30° E
Resolution: 204 meters/pixel
Scale: Firdousi is approximately 96 kilometers (60 miles) in diameter
Incidence Angle: 37.0°
Emission Angle: 14.6°
Phase Angle: 51.7°

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

Saturday, February 25, 2012

Checkov and Schubert Basins


Two prominent basins, Chekhov at the upper left and Schubert at lower right, are both just under 200 km in diameter but have very different appearances. Chekhov has a prominent peak ring and its older age is reflected in the numerous craters that have battered its rim and floor. Schubert's floor is smooth with only a hint of its peak ring peeking through.

Date acquired: October 31, 2011
Image Mission Elapsed Time (MET): 228589200, 228589220, 228589204
Image ID: 956051, 956056, 956052
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: -37.80°
Center Longitude: 303.8° E
Resolution: 655 meters/pixel
Scale: Scene is approximately 700 km (435 miles) across
Incidence Angle: 71.1°
Emission Angle: 15.9°
Phase Angle: 86.8°

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

Friday, February 24, 2012

De Graft Crater and Rays from Hokusai


A colorful view of a complex region is shown in this image. The high-reflectance and hollow-filled floor of de Graft crater is visible at center left, and a similar high-reflectance smaller crater is located to the northeast. Streaking across the scene from north to south are rays from Hokusai crater, located over 1,500 km away.

Date acquired: September 22, 2011
Image Mission Elapsed Time (MET): 225143097, 225143117, 225143101
Image ID: 790098, 790103, 790099
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: 24.00°
Center Longitude: 6.67° E
Resolution: 421 meters/pixel
Scale: De Graft crater is approximately 68 km (42 miles) in diameter
Incidence Angle: 26.8°
Emission Angle: 22.5°
Phase Angle: 39.3°

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

Thursday, February 23, 2012

Brontë and Degas Craters


This image shows a colorful view of Brontë (the large crater in the top right corner) and Degas (the blue-hued crater atop Brontë). These craters are located in Sobkou Planitia, a plains region formed through past volcanic activity.

Date acquired: December 12, 2011
Image Mission Elapsed Time (MET): 232160712, 232160708, 232160704
Image ID: 1125985, 1125984, 1125983
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: 36.44°
Center Longitude: 231.5° E
Resolution: 231 meters/pixel
Scale: Degas crater is 52 km (32 miles) in diameter
Incidence Angle: 59.7°
Emission Angle: 25.2°
Phase Angle: 85.0°

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

Wednesday, February 22, 2012

Shakespeare Impact Basin


For Valentine's Day, it seems appropriate to feature Shakespeare basin, named for the English poet and playwright and author of a famous collection of sonnets, some focusing on love. "Shall I compare thee" to other large basins on Mercury? If so, check out Rembrandt, Tolstoj, Rachmaninoff and Beethoven.

This mosaic was assembled from eight images that were 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: April 26 - 28, 2011
Image Mission Elapsed Time (MET): 212372542, 212415875, 212416002, 212459333, 212459461, 212459565, 212502921, 212503025
Image ID: 181841, 183945, 183946, 185952, 185953, 185954, 188123, 188124
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: 48.5°
Center Longitude: 208° E
Resolution: 240 meters/pixel
Scale: Shakespeare basin has a diameter of 400 km (250 miles)
Incidence Angle: 73°
Emission Angle: 0.6°
Phase Angle: 75°

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

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

Saturday, January 14, 2012

Ghost Crater


This scene, which lies within the Goethe basin, shows a ghost crater that is approximately 45 km in diameter. The crater contains prominent graben (extensional troughs) and is bound by a wrinkle ridge ring that marks the location of the crater rim.

Date acquired: April 29, 2011
Image Mission Elapsed Time (MET): 212590628
Image ID: 192049
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: 81.4°
Center Longitude: 301.9° E
Resolution: 163 meters/pixel
Scale: The ghost crater containing many troughs is approximately 45 km (28 mi.) in diameter.
Incidence Angle: 82.8°
Emission Angle: 5.4°
Phase Angle: 88.2°

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

Friday, January 13, 2012

Hollows in Scarlatti's Basin


Scarlatti is a peak-ring basin with a diameter of 132 kilometers. Just north of the inner peak ring on the basin's floor is a large oblong pit, shown here in the highest resolution ever obtained. The large pit may have formed as a volcanic collapse feature, and this high-resolution view shows many hollows located on the pit's wall. Members of the MESSENGER team are using images like this one to unravel the geologic relationship between Scarlatti's pit and these newly seen hollows.

Date acquired: December 08, 2011
Image Mission Elapsed Time (MET): 231863738
Image ID: 1111610
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 41.53°
Center Longitude: 259.1° E
Resolution: 29 meters/pixel
Scale: This image is approximately 30 kilometers (19 miles) across
Incidence Angle: 81.2°
Emission Angle: 10.7°
Phase Angle: 92.0°

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

Thursday, January 12, 2012

Hollows at the Peaks in Eminescu Crater


The central peaks of Eminescu are revealed here at high resolution, showing off an impressive collection of hollows. Some of these hollows have coalesced into larger formations. North is down in this image.

Date acquired: December 05, 2011
Image Mission Elapsed Time (MET): 231610992
Image ID: 1099314
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 10.9°
Center Longitude: 114.5° E
Resolution: 33 meters/pixel
Scale: This image is approximately 66 km (41 mi.) across
Incidence Angle: 66.2°
Emission Angle: 59.2°
Phase Angle: 125.5°

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

Wednesday, January 11, 2012

Volcanic Vent


This kidney-shaped depression lies along the inner margin of the Caloris basin and was first imaged during MESSENGER's first flyby of the innermost planet. The rimless, non-circular depression is the vent of a small, explosive volcano, similar to other volcanic vents on Mercury. The small number of superposed craters indicates that this feature is relatively young.

Date acquired: June 07, 2011
Image Mission Elapsed Time (MET): 215894570
Image ID: 347724
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 22.5°
Center Longitude: 146.1° E
Resolution: 28 meters/pixel
Scale: The depression is approximately 23 km (14 mi.) across its longest dimension.
Incidence Angle: 39.6°
Emission Angle: 45.5°
Phase Angle: 78.3°

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