Alver Crater

Today's image features a perspective view of the Alver crater, recently named for Estonian poet Betti Alver (1906-1989). Alver's husband was imprisoned and died in Siberia after World War II, leading Alver to stop writing poetry for many years in protest of Soviet rule. She resumed writing poetry in the 1960s, composing the notable 1966 collection Tähetund or "Starry Hour."

To create this image, a portion of the MDIS monochrome basemap was draped over a digital elevation model. The topography has been exaggerated by 5 times to accentuate the crater rim and central peak ring. The view is looking towards the southeast. Alver is a complex crater in the southern hemisphere of Mercury. This perspective view highlights the smooth nature of the basin floor relative to the ejecta blanket and surrounding terrain.

Instrument: Mercury Dual Imaging System (MDIS)
Center Latitude: -67.0°
Center Longitude: 77.9° E
Basemap Resolution: approximately 250 meters/pixel
Digital Elevation Model: Produced by MESSENGER Participating Scientist Bob Gaskell based on MDIS images
Vertical Exaggeration: 5 times actual
Scale: Alver crater is 151.5 km (94.1 miles) across

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

Hurley and L'Engle Craters

Repeat imaging of Mercury's south pole has revealed that a number of craters in the south contain permanently shadowed regions. Because Mercury has only a very small axial tilt, the topography of crater rims, as accentuated in the inset image (shown with five times the vertical exaggeration of the actual topography), blocks sunlight from ever reaching portions of the floors of some polar craters.

This image features two such permanently shadowed craters which were recently named. Hurley crater, named for Australian James Francis Hurley (1885-1962), photographer of the famous Shackleton Expedition to Antarctica, is 67 km (42 mi.) wide and located within 3° of Mercury's south pole. The slightly smaller (62 km or 39 mi. wide) L'Engle crater is located to the east of Hurley. (Note that in the inset perspective image the view is towards the south). L'Engle crater is named for American author Madeleine L'Engle (1918-2007), best known for her young-adult novels including 'A Wrinkle in Time'. 'A Wrinkle in Time' blends adventure with quantum physics as it follows young heroine Meg on her journey through space to rescue her scientist father.

This primary image was acquired as part of MDIS's campaign to monitor the south polar region of Mercury. By imaging the polar region approximately 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 primary mission, MDIS's WAC was used to monitor the south polar region for the first Mercury solar day (176 Earth days), and MDIS's NAC made repeated images of the south polar region during the second Mercury solar day. The inset image is a portion of the MDIS monochrome map draped over the Gaskell digital elevation model (with 5 times vertical exaggeration), as was also done for Monday's featured image.

Date acquired: August 03, 2011
Image Mission Elapsed Time (MET): 220899377
Image ID: 587366
Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
WAC filter: 7 (748 nanometers)
Center Latitude: -85.07°
Center Longitude: 67.57° E
Scale: The inset box is about 280 km (174 mi.) wide
Incidence Angle: 85.0°
Emission Angle: 23.4°
Phase Angle: 94.8°

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

Lovecraft and Roerich Craters

Today's image features a perspective view of two of the newly named craters near Mercury's south pole. To create this image, a portion of the MDIS monochrome basemap was draped over a digital elevation model. The topography has been exaggerated by 7 times to accentuate the rugged terrain formed by numerous overlapping craters.

In the foreground, sunlight highlights much of the rim of the dark Lovecraft crater, named for the American horror author Howard Phillips Lovecraft (1890-1937). The larger Roerich crater, named for the Russian painter Nicholas Roerich (1874-1947), lies slightly to the north of Lovecraft crater. One of Lovecraft's most famous works, 'At the Mountains of Madness' takes place on a scientific expedition to the south pole, and references Roerich's artwork--in particular, his paintings of the Tibetan plateau and the Himalayan Mountains. Portions of Lovecraft crater are shrouded in permanent darkness, and host radar-bright material. Similar deposits at the north pole have been associated with water ice and unusually dark material.

Instrument: Mercury Dual Imaging System (MDIS)
Center Latitude: -85.10°
Center Longitude: 284.8° E
Basemap Resolution: approximately 250 meters/pixel
Digital Elevation Model: Produced by MESSENGER Participating Scientist Bob Gaskell based on MDIS images
Vertical Exaggeration: 7 times actual
Scale: Roerich crater is 111.7 km (69.4 miles) across.

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

A Tribute to Messenger

This video showcases a small sampling of the thousands of images taken by the spacecraft, as well as animations illustrating how MESSENGER moves in orbit and how its orbit has changed during the mission.

The opening sequence is from the approach images from the first flyby in 2008. The first animation to follow (at 0:15) shows MESSENGER in its primary mission 12-hour orbit. The relevance of the November 9, 2011, date is that this was when the MESSENGER team was advised that NASA had approved the proposal for an extended mission, allowing the mission to continue making new observations from March 2012 to March 2013. The animation at 0:22 gives you an idea of the movement and gyrations ("dancing") that the spacecraft undergoes while it performs a schedule packed full of observations that take place over one Earth day. The animation sequence at 0:59 gives you a "top down" view over Mercury's north pole from when MESSENGER first went into orbit until several months into the extended mission. The apparent size of the orbit shrinks from the start of the animation to the end, as shortly into the extended mission, MESSENGER's orbital period was shrunk from 12-hours to 8-hours. The animation sequence at 1:44 shows MESSENGER's "dance" on the first day of the extended mission. The other images and embedded movies can be found in the Gallery section of the MESSENGER website.

Some highlight images of note include:

At 0:48 - Blue rays of Bek crater
At 0:54 - Basho crater
At 0:57 - Poe crater in Caloris basin
At 1:17 - MASCS instrument surface scans in ultraviolet and infrared
At 1:19 - A perspective view of the northern polar region, color-coded to MLA topography
At 1:27 - Rembrandt impact basin
At 1:29 - Rembrandt impact basin superimposed on the US for size comparison
At 1:34 - Rachmaninoff impact basin, 3D effect crated using the digital elevation model
At 1:34 - Debussy crater
At 1:58 - Beagle rupes
At 2:04 - Mosaic view of north pole, showing the shadowed regions
At 2:06 - As previous, with superimposed radar data indicating likely water-ice deposits
At 2:11 - A volcanic vent near the edge of Caloris basin
At 2:34 - Derain crater
At 2:36 - Disney crater and two unnamed craters that resemble Mickey Mouse
At 2:38 - Basho crater while the Sun is low in the sky
At 2:40 - Basho crater again, but now with the Sun nearly overhead
At 2:45 - Degas crater
At 2:58 - 'Weird terrain' at the Caloris antipode
At 3:03 - Waters crater with the 'blue tongue' of dark impact melt material
At 3:10 - Seuss crater
At 3:13 - Caloris basin
At 3:15 - Pit in Scarlatti crater, with prominent hollows on the pit rim
At 3:17 - Enhanced color of Caloris basin
At 3:22 - A lava channel that had flowed into the Kofi crater
At 3:29 - More detail of Caloris basin floor
At 3:30 - The young, bright-rayed Mena crater
At 3:37 - Central peaks of Eminescu crater, with hollows around the bases of the peaks
At 3:39 - Apollodorus and Pantheon fossae
At 3:41 - The hollows on the floor of Sander crater

The MESSENGER spacecraft is the first ever to orbit the planet Mercury, and the spacecraft's seven scientific instruments and radio science investigation are unraveling the history and evolution of the Solar System's innermost planet. Visit the Why Mercury? section of this website to learn more about the key science questions that the MESSENGER mission is addressing. During the one-year primary mission, MDIS acquired 88,746 images and extensive other data sets. MESSENGER is now in a year-long extended mission, during which plans call for the acquisition of more than 80,000 additional images to support MESSENGER's science goals.

Video credit: Images and animation stills courtesy NASA/Johns Hopkins University Applied Physics Laboratory/Carnegie Institution of Washington. Music: "Mercury Ridge" by Simon Wilkinson (thebluemask.com). Video creation and time-lapse animations by Mark 'Indy' Kochte.

Thrust Fault Scarp on Mercury

The figure above shows an oblique view of a 280 km long scarp. The color scale on this figure represents elevation in which red is high and blue is low. This scarp is interpreted to be a surface-breaking thrust fault. Thrust faults are surface manifestations of the shrinkage of the planet resulting from the cooling of its interior. Notice that the terrain on the left side of the scarp stands about 2 km higher than that of the right side of the scarp. To give you a sense of the scale of this scarp, the state of Delaware has been superposed on the figure.

Center Latitude: 58.18°
Center Longitude: 307.69° E
Scale: The crater that is being cross-cut by this scarp is about 108 km (67 mi.) in diameter.

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

Rachmaninoff Impact Basin

This is a still image taken from a rotating movie of Mercury's Rachmaninoff impact basin. An enhanced-color image has been draped over a digital elevation model of the surface. The vertical exaggeration is 7 times. The basin's outer rim is about 306 km in diameter and the inner (peak) ring is about 140 km in diameter. The smooth plains within the center appear tan in this presentation, emphasizing their compositional contrast with the dark, bluer rocks that form the peak ring mountains. Images from the Mercury Dual Imaging System on board NASA's MESSENGER spacecraft were processed to provide the color and elevation information used to create this view.

The color base map shown here consists of MDIS images taken through eight different color filters. It is part of a global color map that covers more than 99% of Mercury's surface with an average resolution of about 1 kilometer per pixel.

Instrument: Wide Angle Camera (WAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: 27.8°
Center Longitude: 58° E

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

Note: For a video showing a 360-degree view of this impact basin, click here.

Debussy Crater

Here we have two images of the impact crater named Debussy. The one on the left is from MESSENGER's monochrome base map. The one on the right is a complement from the stereo base map. Because of the differing viewing perspectives, the images can be combined to derive an elevation map (digital terrain model) of the surface.

The left image was acquired as part of MDIS's high-resolution surface morphology base map. The surface morphology base map will cover more than 90% of Mercury's surface with an average resolution of 250 meters/pixel (0.16 miles/pixel or 820 feet/pixel). Images acquired for the surface morphology base map typically have off-vertical Sun angles (i.e., high incidence angles) and visible shadows so as to reveal clearly the topographic form of geologic features. The right image was acquired as part of MDIS's high-resolution stereo base map. The stereo base map is used in combination with the surface morphology base map to create high-resolution stereo views of Mercury's surface, with an average resolution of 250 meters/pixel (0.16 miles/pixel or 820 feet/pixel) or better. During MESSENGER's one-year mission, the surface morphology base map is acquired during the first 176 days, and the second 176 days are used to acquire the complementary stereo base map, which includes the image here.

Left image:
Date acquired: July 31, 2011
Image Mission Elapsed Time (MET): 220581440
Image ID: 572963
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: -34.04°
Center Longitude: 11.25° E
Resolution: 284 meters/pixel
Incidence Angle: 67.2°
Emission Angle: 35.2°
Phase Angle: 102.4°

Right image:
Date acquired: January 19, 2012
Image Mission Elapsed Time (MET): 235424544
Image ID: 1283627
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Center Latitude: -33.95°
Center Longitude: 13.18° E
Resolution: 161 meters/pixel
Incidence Angle: 76.9°
Emission Angle: 23.3°
Phase Angle: 89.2°
Scale: Debussy crater has a diameter of about 80 km (50 mi.)

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

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